Liquid dispensing systems with gas removal and sensing capabilities

ABSTRACT

A fluid dispensing system for delivering a gas free chemical. The fluid dispensing system includes a gas separation device that separates a liquid from bubbles entrained in the liquid and accumulating the gas from the bubbles in a reservoir. A level sensor detects if the liquid in the reservoir drops too low, triggering the gas separation device to vent the gas from the reservoir. An empty detect apparatus that detects pressure droop of the liquid may also be implemented for taking appropriate action.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 13/520,557, filed Jul. 27, 2012, which is a §371 ofInternational Patent Application No. PCT/US2011/020236, filed Jan. 5,2011, which claims the benefit of U.S. Provisional Patent ApplicationNo. 61/292,852 filed Jan. 6, 2010, all of which are hereby incorporatedby reference herein in their entireties.

TECHNICAL FIELD

The present invention relates to dispensing systems, such as may beutilized to dispense fluid materials for use thereof, and relatedsensing systems. In a specific aspect, the invention relates topressure-dispensing systems, wherein liquid or other fluid material isdischarged from a source vessel by displacement with a pressurizedmedium, e.g., air or liquid, and to associated aspects relating tofabrication, sensing, operational processes, and deployment of suchsystems.

BACKGROUND

In many industrial applications, chemical reagents and compositions arerequired to be supplied in a high purity state, and specializedpackaging has been developed to ensure that the supplied material ismaintained in a pure and suitable form, throughout the package fill,storage, transport, and ultimate dispensing operations.

In the field of microelectronic device manufacturing, the need forsuitable packaging is particularly compelling for a wide variety ofliquids and liquid-containing compositions, since any contaminants inthe packaged material, and/or any ingress of environmental contaminantsto the contained material in the package, can adversely affect themicroelectronic device products that are manufactured with such liquidsor liquid-containing compositions, rendering the microelectronic deviceproducts deficient or even useless for their intended use.

As a result of these considerations, many types of high-purity packaginghave been developed for liquids and liquid-containing compositions usedin microelectronic device manufacturing, such as photoresists, etchants,chemical vapor deposition reagents, solvents, wafer and tool cleaningformulations, chemical mechanical polishing compositions, colorfiltering chemistries, overcoats, liquid crystal materials, etc.

One type of high-purity packaging that has come into such usage includesa rigid, substantially rigid, or semi-rigid overpack containing a liquidor liquid-based composition in a flexible liner or bag that is securedin position in the overpack by retaining structure such as a lid orcover. Such packaging is commonly referred to as “bag-in-can” (BIC),“bag-in-bottle” (BIB) and “bag-in-drum” (BID) packaging. Packaging ofsuch general type is commercially available under the trademark NOWPAKfrom Advanced Technology Materials, Inc. (Danbury, Conn., USA).

Preferably, a liner comprises a flexible material, and the overpackcontainer comprises a wall material that is substantially more rigidthan said flexible material. Rigid or semi-rigid overpack of thepackaging may be formed (for example) of a high-density polyethylene orother polymer or metal, and the liner may be provided as a pre-cleaned,sterile collapsible bag of a polymeric film material, such aspolytetrafluoroethylene (PTFE), low-density polyethylene, medium-densitypolyethylene, PTFE-based laminates, polyamide, polyester, polyurethane,or the like, selected to be inert to the material (e.g., liquid) to becontained in the liner. Multilayer laminates comprising any of theforegoing materials may be used. Exemplary materials of construction ofa liner further include: metalized films, foils, polymers/copolymers,laminates, extrusions, co-extrusions, and blown and cast films.Liner-based packaging of such general type is commercially availableunder the trademark NOWPAK from Advanced Technology Materials, Inc.

In use of liner-based packaging to dispense liquids and liquid-basedcompositions, the liquid or composition is dispensed from the liner byconnecting a dispensing assembly including a dip tube or short probe toa port of the liner, with the dip tube being immersed in the containedliquid. Fluid (e.g., gas) pressure is applied to the exterior surface ofthe liner (i.e., in the space between the liner and a surroundingoverpack container), to progressively collapse the liner and therebyforce liquid through the dispensing assembly for discharge to associatedflow circuitry to flow to an end-use tool or site. Such operation may becalled liner-based pressure dispensing. Use of a liner to contain aliquid to be dispensed prevents direct contact with pressurized gasarranged to exert pressure against the liner.

A simplified schematic of a conventional liner-based package 60 isprovided in FIG. 1A, showing a liner 62 having (surrounding) an interiorvolume containing a liquid 68, with the liner 62 disposed within anoverpack container 61. An interstitial space 63 is provided between theliner 62 and the overpack container 61, and is in fluid communicationwith a pressurized gas source 65. Addition of pressurized gas to theinterstitial space 63 compresses the liner 62 to cause liquid 68 to flowthrough a diptube 64 out of the container to a process tool or otherpoint of use 66.

Headspace (extra air or gas at the top of a liner) and microbubblespresent a significant process problem for liquid dispensing fromliner-based packages, such as in flat panel display (FPD) and integratedcircuit (IC) manufacturing facilities. Headspace gas may derive from thefilling operation, in which the package is less than completely filledwith the liquid. Less than complete filling of the package may benecessary in order to provide a headspace as an expansion volume toaccommodate changes in the ambient environment of the package, such astemperature changes that cause the liquid to expand during transport ofthe package to a location where the package will be placed in dispensingoperation.

While maintenance of headspace in a liner-based package may be desirableduring package transport, such headspace may be detrimental to fluiddispensing and/or use. Gas from the headspace may become entrained inthe liquid being dispensed from a liner-based pressure package andproduce a heterogeneous, a multi-phase dispensed fluid stream that isdeleterious to the process or product for which the dispensed liquid isbeing utilized. Further, the presence of gas from the headspace in thedispensed liquid can result in malfunction or error in operation offluid flow sensors, flow controllers, and the like.

A related problem, incident to the use of packages containing liquidcompositions, is permeation or in-leakage of gas into the containedliquid and solubilization and bubble formation in the liquid. In thecase of liner-based packages, gases exterior to the liner may permeatethrough the liner (e.g., through slightly permeable film materials,seams between liner panels, and/or pinholes formed in liner panels) intothe contained liquid. Where liner-based packages are utilized forpressure dispense operation, the pressurizing gas itself, e.g., air ornitrogen, may permeate through the liner material and become dissolvedin the liquid in the liner. When the liquid subsequently is dispensed,pressure drop in the dispensing lines and downstream instrumentation andequipment may cause liberation of formerly dissolved gas, resulting inthe formation of bubbles in the stream of dispensed liquid, withconsequent adverse effect analogous to those resulting from entrainedheadspace gas. It would therefore be desirable to remove headspace gasprior to initial dispensation. It would also be desirable to permitcontinued removal of liberated gas after liquid dispensation hascommenced. It would further be desirable to accomplish gas removalrapidly while reducing the potential for microbubble formation.

In the manufacture of semiconductor products and other microelectronicproducts, the presence of bubbles, even those of microscopic size(microbubbles), can result in an integrated circuit or flat-paneldisplay being deficient or even useless for its intended purpose. Ittherefore is imperative for all extraneous gas to be removed from theliquid utilized for the manufacture of such products.

In use of a typical liner-based package, the package is pressurized anda venting valve is opened to allow headspace gas to flow out of theliner. After headspace gas is exhausted, liquid enters the headspace gasdischarge line, a gas venting valve is closed, and another valve isopened to dispense only liquid in a liquid discharge line. When thepackage signals an empty detect condition, e.g., by monitoring ofpressure of the dispensed fluid, and detection of a drop in the pressureas a function of time, the connector or other coupling device joined tothe vessel containing the liner can be removed from the exhaustedvessel, and placed on a fresh (e.g., full) container, to provide forcontinued dispensing operation. Due to presence of liquid in theheadspace removal line, a timer may be used to bypass the liquid sensoruntil headspace gas arrives again. Thereafter, liquid reenters the ventline and the sensor is “re-activated” with the timer to close the ventvalve. Such arrangement, however, is susceptible to failure modesinvolving occurrence of the following events: (i) the timer is not setcorrectly and transmits a false signal indicating that the headspace hasbeen removed; (ii) headspace varies from one filled package to another,and settings that are selected for one package are not appropriate foranother, so that the headspace gas is not correctly removed; (iii)bubbles present in the headspace gas vent line create a false indicationof headspace gas removal; and (iv) remaining (previously present) liquidin the headspace vent line can give a false indication of headspace gasremoval.

Additionally, in the storage and dispensing of liquids and liquid-basedcompositions from liner packages, it is desirable to manage thedispensing operation so that the depletion or approach to depletion ofthe dispensed material is detected so that termination of a downstreamoperation, or switchover to a fresh package of material, is able to betimely effected. Reliability in end-stage monitoring of the dispensingoperation, and particularly in detection of an empty or approachingempty condition, therefore enables optimum utilization of linerpackages, and is a desired objective for design and implementation ofsuch packaging. It can be difficult to reliably and economically detectan empty condition or approach to empty condition indicative ofexhaustion of liquid from a package or reservoir for dispensation to adownstream process. Upon completion of detection, a second source ofliquid is preferred to be automatically switched over, therebyeliminating any additional downstream operational concerns. For example,a switchover reservoir adapted to supply fluid deriving from saidpressure dispense package may be utilized for dispensing when a pressuredispense package is emptied or nearly emptied of said fluid.

Another problem associated with packages from which liquids aredispensed for industrial processes such as manufacture microelectronicdevice products, relates to the fact that the liquids in many cases areextraordinarily expensive, as specialty chemical reagents. It thereforeis necessary from an economic perspective to achieve as complete autilization of the liquid from a package as possible, so that nosubstantial residual amount of liquid remains in the package after thedispensing operation has been completed. For such reason, it isdesirable to monitor the dispensing operation in a manner that permitsdetermination of the endpoint of such operation. There is a continuingeffort in the art to provide efficient endpoint detectors that minimizethe amount of liquid residuum in the package.

Certain problems with liner-based dispensing packages have beenaddressed by systems and methods disclosed in International PatentApplication Publication No. WO/2007/146892 (“the '892 publication”),which is assigned to Advanced Technology Materials, Inc., shares severalcommon inventors with the present application, and is herebyincorporated by reference herein. The '892 publication discloses highlyintegrated connectors that provide the following utilities: liquiddispensing, headspace gas removal, pressure relief, pressuremeasurement, and reservoir gas/liquid level control (i.e., via sensingand valving). The accompanying FIG. 1 (which is adapted from FIG. 20A ofthe '892 publication) provides a cross-sectional view of at least aportion of such a connector 1 including an integrated reservoir 16 and asensor 55 proximate to an interface between liquid 58 and gas (i.e.,disposed above the liquid 58) within the reservoir 16, to sense acondition in which a gas pocket has accumulated along an upper portionof the reservoir 16, to permit gas to be periodically and automaticallyexpelled from the reservoir 16 during dispensing operation. Although notfully illustrated in FIG. 1, the connector 1 includes a probe (in whicha central conduit 6 is defined) arranged to extend downward into aliner. The central conduit 6 extends in the middle of a container and/orliner (not shown) and the reservoir 16 disposed within the body 24 ofthe connector 1. The central conduit 6 has a central bore accommodatingupward gas/liquid flow, and an open upper end 10 allowing the upflowinggas/liquid during dispensing operation to overflow the upper end 10 andissue into the reservoir 16. A pressurized gas supply line 3 is used tosupply pressurized gas to a space between a liner and an overpackcontainer to promote dispensation of the liquid contents of the linerinto the connector 1. A pressure sensing line 21 and pressure sensor 22are arranged to sense pressure in the central conduit 6. A gas conduit18, which is in fluid communication with the reservoir 16 at an upperportion thereof, is communicatively coupled to an actuatable gas outletvalve 34. A corresponding liquid outlet conduit 19 is in fluidcommunication with the reservoir 16 at a lower portion thereof and iscommunicatively coupled to an actuatable liquid outlet valve 30.

Although integrated reservoir systems disclosed in the '892 publicationachieve their intended purpose, various considerations have demonstratedunmet needs for modifications or enhancements to such systems.

Liner-based pressure dispensing containers are often installed indedicated material dispensing enclosures or cabinets with numerous otherfluid lines and fluid control components. Presence of an integratedreservoir and other components requires presence of significant space(volume) above a pressure dispensing container, and also requiresmultiple electrical and fluid connections to be made within that space.It would be desirable to reduce volumetric requirements immediatelyproximate to pressure dispensing containers, and also reduce the numberof electrical and fluid connections that need to be made immediatelyproximate to such containers.

In case a liner within a pressure dispense package according to the '892publication should fail, it may be difficult or impossible to continuedispensation of a liquid composition with the liner due to flow of gasfrom a pressurized gas inlet through the central conduit (e.g., centralconduit 6 as illustrated in the accompanying FIG. 1), to the exclusionof liquid flow through such central conduit. It would be desirable toprovide for continued flow of liquid through a connector of aliner-based pressure dispense assembly even if the integrity of theliner should be compromised.

Sole reliance on gravimetric separation between liquid and gas within areservoir such as disclosed in the '892 publication may not provideample separation in case very high viscosity liquids and/or high liquiddispensing rates are used. That is, depending on the liquid viscosityand flow rate in a gravimetric reservoir separation system, upwardmotion of gas bubbles in a reservoir (i.e., toward a gas outlet arrangedat an upper portion thereof) may not be sufficiently fast to overcomedownward motion of liquid in the reservoir (i.e., toward a liquid outletarranged at a bottom portion thereof), such that some bubbles may beundesirably entrained in flow of liquid through the liquid outletassociated with the reservoir. It would be desirable to ensure that gasbubbles are not entrained in liquid dispensed to a point of use over awide range of liquid viscosities and liquid flow rates.

Prior methods of joining a diptube to a mating (e.g., recess-defining)structure have occasionally led to tube cracking Certain joining methodshave involved tube flaring and other techniques, which are also laborintensive. It would be desirable to accommodate mating of a diptube to amating structure while avoiding the foregoing issues.

When dispensing highly opaque liquids (e.g., pigmented color filtermaterials and used for coating flat panels in the manufacture of displaymonitors, and similar fluids), conventional systems and methods fordetecting presence or absence of liquid may be insufficient, sinceoptical measurement techniques may be ineffective and capacitancemeasurement techniques may be insufficiently sensitive and/or reliableas applied to such liquids. It would be desirable to enhance reliabilityof detecting opaque fluids for dispensing of same to desired points ofuse, such as manufacturing process tools for flat panel displays.

When dispensing fluid from a liner-based pressure dispense packageincluding an overpack container containing a thin film-based linerdefining an interior volume arranged to contain source material(including liquid), gas trapped within folds of a liner may be releasedduring dispensation and may be dissolved in the source material. Thatis, conventional liners may embody two-dimensional designs (e.g.,including front and back panels, optionally including side and/or endpanels) that are peripherally bonded to one another) that are notconformal to the shape of an associated overpack container, and gas maybe trapped in folds of such a liner when the liner is inflated andfilled. Release of such gas during pressure dispensing enables such gasto be dissolved in source material. When the source material issaturated with gas, the source material or container (containing sourcematerial) must be replaced to avoid dispensation of source materialcontaining gas bubbles. Such replacement may be necessary long beforesource material is exhausted from the pressure dispense container,thereby wasting source material and potentially reducing utilization ofa process tool while a pressure dispense container is changed. Based ontesting and simulation, Applicants have been determined that the maximumamount of fold gas at the upper limit should not surpass 500 ml for a200 liter liner.

FIG. 10 shows dissolved gas saturation pressure (in Pascals) versus time(in days) for simulations modeling gas released from folds duringpressure dispense of fluid from seven different 200 liter collapsiblefilm-based container liners (e.g., simulations including a liner with 0cm radius fold containing 0 ml of fold gas, a 1 cm radius foldcontaining 17 ml of fold gas, 2 cm radius fold containing 133 ml of foldgas, a 3 cm radius fold containing 447 ml of fold gas, 4 cm radius foldcontaining 1061 ml of fold gas, a single Z-fold configuration, and adouble Z-configuration, respectively). The volume of each bubble iscalculated assuming the bubble is under atmospheric pressure, while theradius of each bubble is calculated assuming the bubble is subjected to30 psi dispense pressure. As shown in FIG. 10, a double Z-fold linerconfiguration tends to trap more gas (resulting in higher gas saturationpressure) than a single Z-fold liner. Based on the simulationrepresented in FIG. 10, liquid source material becomes saturated (e.g.,with 500 ml of) fold gas following dispensation of about 88% of thesource material.

Applicants have determined that fold gas is not released from folds of apressure dispensing liner until very late in the dispensation process.This means a liner with relatively high rigidity and poor conformance toan overpack container will have folds and be susceptible to thedissolved gas. FIG. 11 shows the release of fold gas with respect totime for a first liner with a single Z-fold configuration (lower curve)and for a second liner with a double Z-fold configuration (upper curve).Such figure shows that a larger amount of fold gas is trapped within aliner having a double Z-fold configuration than in a liner having asingle Z-fold configuration. FIG. 11 shows that a substantial amount offold gas remains within a liner during the last 25 percent of thedispense process. The issue is also exacerbated by the high ratio of gasto remaining source material within the liner near the end of thedispense process (when the majority of the liquid source material hasbeen depleted from the liner).

Whether or not in conjunction with presence of fold gas, presence of anypin holes or larger opening (i.e., a breach) in a liner tend to allowingress of pressurization gas into the liner and gas headspace, therebyhastening attainment of (undesirable) saturation of source material withgas.

It would be desirable to manage the effects of fold gas and the effectsof a failed liner in pressure dispensing of source material. It would bedesirable to increase the percentage of dispensed source materialwithout reaching the gas saturation level (e.g., to enable dispensationof a very high percentage (e.g., >98% or >99%) of source material beforea gas-saturated condition is reached) in order to reduce waste of sourcematerial and extend the time between replenishment of source materialcontainers.

The art therefore continues to seek improvements in dispensing packages,dispensing systems, dispensing methods, and associated sensingapparatuses.

SUMMARY

The present invention relates to fluid dispensing systems and methodsthat overcome various issues present in conventional systems.

In one aspect, the invention relates to a fluid dispensing systemcomprising: a pressure dispense package including a vessel with aninterior volume arranged to contain a fluid for pressure dispensing, thevessel including a vessel opening; and a dispensing assembly adapted tomate with the vessel proximate to the vessel opening, the dispensingassembly including: a gas extraction opening exposed to the interiorvolume; a liquid extraction opening exposed to the interior volume; agas extraction conduit extending between the gas extraction opening anda gas outlet; and a liquid extraction conduit extending between theliquid extraction opening and a liquid outlet; wherein the gasextraction conduit is distinct from the liquid extraction conduit.

In another aspect, the invention relates to a connector arranged fordispensing liquid-containing source material from a liner-based pressuredispense package including an overpack container containing a linerdefining an interior volume arranged to contain said source material,the connector comprising a gas extraction conduit arranged to extractgas from the interior volume, a liquid extraction conduit arranged toextract liquid from the interior volume, and a pressurization gasconduit arranged to supply gas to an interstitial space between theliner and the overpack container.

In a further aspect, the invention relates to structure arranged for usewith a pressure dispense package including a vessel with an interiorvolume arranged to contain a fluid for pressure dispensing, the vesselincluding a vessel opening, wherein the structure comprises: a bodydefining a longitudinal bore and a gas extraction opening, wherein alower portion of the longitudinal bore is arranged to receive a diptubearranged to extend into the interior volume and having a liquidextraction opening, and an upper portion of the longitudinal bore isarranged to receive a connector, the connector defining a gas extractionconduit in fluid communication with a gas outlet and defining a liquidextraction conduit in fluid communication with a liquid outlet; whereinthe gas extraction opening is exposed to the interior volume and is influid communication with the gas extraction conduit, and the liquidextraction opening is exposed to the interior volume and is in fluidcommunication with the liquid extraction conduit.

A further aspect of the invention relates to method utilizing a pressuredispense package including a vessel with an interior volume arranged tocontain fluid for pressure dispensing, the method comprising: insertinga connector defining a gas extraction conduit and a liquid extractionconduit into a dispensing assembly defining (i) a longitudinal borearranged to permit fluid communication with a liquid extraction openingexposed to the interior volume and (ii) a lateral bore arranged topermit fluid communication with a gas extraction opening exposed to theinterior volume, wherein said insertion of the connector into thedispensing assembly simultaneously effects fluid communication (a)between the liquid extraction conduit and the liquid extraction openingand (b) between the gas extraction conduit and the gas extractionopening; extracting gas from the interior volume through the gasextraction opening and the gas extraction conduit; and pressuredispensing liquid from the interior volume through the liquid extractionopening and the liquid extraction conduit.

A still further aspect of the invention relates to a gas removalapparatus adapted to remove gas from a liquid stream, the apparatuscomprising: a reservoir body defining an interior volume includingtherein a filtration medium adapted to permit passage of liquid butprevent passage of bubbles, the reservoir body having a fluid inlet,having a liquid outlet arranged to receive liquid passing through thefiltration medium, and having a gas outlet arranged to receive gasaccumulated from bubbles prevented from passing through the filtrationmedium; and a pressure transducer in sensory communication with theinterior volume and arranged to generate an output signal indicative ofpressure within the interior volume.

Yet another aspect relates to a method comprising: (a) venting gas fromwithin an interior volume of a collapsible liner disposed in an overpackcontainer of a pressure dispense package, the liner further containing aliquid, wherein the gas is vented through a gas extraction conduit and agas outlet defined in a dispensing assembly; (b) supplying pressurizedgas to an interstitial space between the liner and the overpackcontainer to compress the liner and thereby dispense liquid from theinterior volume through a liquid extraction conduit and a liquid outletdefined in the dispensing assembly, wherein the liquid extractionconduit is distinct from the gas extraction conduit; (c) flowing liquidreceived from the liquid output through a reservoir body disposeddownstream of the dispensing assembly, wherein the reservoir bodydefines an interior volume including therein a filtration medium adaptedto permit passage of liquid but prevent passage of bubbles, thereservoir body having a reservoir liquid outlet arranged to receiveliquid passing through the filtration medium, and having a reservoir gasoutlet arranged to receive gas accumulated from bubbles prevented frompassing through the filtration medium; and (d) venting gas from thereservoir gas outlet.

Another aspect relates to an apparatus adapted to detect presence offluid or change in phase of flowing fluid within a fluid circuit, theapparatus comprising: a first thermistor in sensory communication withthe fluid at a first location within the fluid circuit, the firstthermistor arranged to be driven at a first current level sufficient tocause self-heating of the first thermistor upon exposure of a sensingportion thereof to gas; a second thermistor in sensor communication withthe fluid at a second location within the fluid circuit, the secondthermistor arranged to be driven at a second current level that issubstantially lower than the first current level; a signal processingelement arranged to receive a first output signal of the firstthermistor and a second output signal of the second thermistor, and todetermine presence of fluid or change in phase of flowing fluid withinthe fluid circuit based on comparison of the first output signal and thesecond output signal.

Yet another aspect relates to a method for sensing presence of fluid orchange in phase of flowing fluid within a fluid circuit, utilizing afirst thermistor in sensory communication with the fluid at a firstlocation within the fluid circuit and utilizing a second thermistor insensory communication with the fluid at a second location within thefluid circuit, the method comprising: driving the first thermistor at afirst current level sufficient to cause self-heating of the firstthermistor upon exposure of a sensing portion thereof to gas; drivingthe second thermistor at a second current level that is substantiallylower than the first current level; and comparing a first output signalof the first thermistor and a second output signal of the secondthermistor to determine presence of fluid or change in phase of flowfluid within the fluid circuit based on such comparison.

Still another aspect relates to an apparatus adapted to detect presenceof fluid or change in phase of flowing fluid within a fluid circuit, theapparatus comprising: a heating element arranged to dissipate heat intofluid at a first location within the fluid circuit; a first sensingelement arranged in sensory communication with the first heating elementand the fluid, and adapted to generate a first sensing element outputsignal correlative of temperature of the first heating element; a secondsensing element arranged in sensory communication with the fluid at asecond location within the fluid circuit, and adapted to generate asecond sensing element output signal correlative of temperature of thefluid at the second location; and a signal processing element arrangedto receive the first sensing element output signal and the secondsensing element output signal, and to determine presence of fluid orchange in phase of flowing fluid within the fluid circuit based oncomparison of the first sensing element output signal and the secondsensing element output signal.

Another aspect relates to a fluid dispensing system arranged fordispensation of fluid to a point of use, the fluid dispensing systemcomprising: a first pressure dispense apparatus including a first vesselwith a first interior volume arranged to contain a fluid forpressure-mediated dispensing; a second pressure dispense apparatusincluding a second vessel with a second interior volume arranged tocontain fluid for pressure-mediated dispensing; at least one ventablereservoir arranged to receive fluid from at least one of the firstinterior volume and the second interior volume; at least one sensingelement arranged to generate an output signal correlative ofdispensation of a desired amount of fluid from, or correlative of anapproach to gas saturation of fluid dispensed by, the first pressuredispense apparatus; at least one control element arranged to dispensefluid from the second pressure dispense apparatus for combining fluiddispensed from the second pressure dispense apparatus with fluiddispensed from the first pressure dispense apparatus, responsive to theoutput signal or signal derived from the output signal; and adispensation conduit arranged to receive fluid dispensed from the firstpressure dispense apparatus and to receive fluid from the secondpressure dispense apparatus, and to convey said fluid to the point ofuse.

Yet another aspect relates to a method of dispensing fluid, the methodcomprising: dispensing fluid from a first pressure dispense apparatuscomprising a first vessel defining a first interior volume, and removinggas from the fluid dispensed from the first pressure dispense apparatus;sensing a condition and generating an output signal correlative ofdispensation of a desired amount of fluid from, or correlative of anapproach to gas saturation of fluid dispensed by, the first pressuredispense apparatus; responsive to the output signal or a signal derivedfrom the output signal, dispensing fluid from a second pressure dispenseapparatus comprising a second vessel defining an interior volume, andremoving gas from the fluid dispensed from the second pressure dispenseapparatus; and combining a flow of fluid dispensed from the secondpressure dispense apparatus with a flow of fluid dispensed from thefirst pressure dispense apparatus, for dispensation of the combined flowto a point of use.

In another aspect, any one or more features of the foregoing aspectsand/or any other aspects and features disclosed herein may be combinedfor additional advantage.

Other aspects, features and embodiments of the invention will be morefully apparent from the ensuing disclosure and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a simplified schematic side cross-sectional view of aliner-based pressure dispense package in the related art, as disclosedin U.S. Pat. No. 7,172,096.

FIG. 1B is a cross-sectional view of at least a portion of areservoir-containing connector for a liner-based pressure dispensepackage in the related art, as disclosed in International PatentApplication Publication No. WO/2007/146892.

FIG. 2 is a simplified schematic cross-sectional view of a connector fora pressure dispense package according to one embodiment of the presentinvention, the connector including a gas extraction conduit and a liquidextraction conduit independent of the gas extraction conduit.

FIG. 3 is a schematic cross-sectional view of a reservoir body arrangedfor placement downstream of a dispense package or dispensing assemblyand including therein a filtration medium adapted to permit passage ofliquid but prevent passage of bubbles, with a pressure transducer insensory communication with the interior volume, according to oneembodiment of the present invention.

FIG. 4A is a side cross-sectional view of a connector, liner fitmentadapter, and diptube adapted for use with a pressure dispense packageaccording to one embodiment of the present invention.

FIG. 4B includes the side cross-sectional view of the connector, linerfitment adapter and diptube of FIG. 4A, and a simplified schematic viewof downstream sensing and flow control components, according to oneembodiment of the present invention.

FIG. 5A is a side elevation view of a liner fitment adapter adapted foruse with a pressure dispense package, according to one embodiment of thepresent invention.

FIG. 5B is a perspective assembly view of the liner fitment adapter ofFIG. 5A.

FIG. 5C is a cross-sectional view of the liner fitment adapter of FIGS.5A-5B.

FIG. 6A is a side cross-sectional view of a connector, closure, linerfitment, and liner fitment adapter arranged for use with a pressuredispense package, according to one embodiment of the present invention.

FIG. 6B is a side elevation view of a diptube suitable for use with theliner fitment adapter illustrated in FIG. 6A.

FIG. 7A is a side cross-sectional view of a connector, closure, linerfitment, and liner fitment adapter arranged for use with a pressuredispense package, according to one embodiment of the present invention.

FIG. 7B is a side elevation view of a diptube suitable for use with theliner fitment adapter illustrated in FIG. 7A.

FIG. 8 is a schematic illustrating interconnections between variouscomponents of a fluid dispensing system including multiple temperaturesensing elements and a signal processing element arranged to determinepresence of fluid or change in phase of flowing fluid based oncomparison of outputs of the temperature sensing elements.

FIG. 9 is a circuit diagram modeling electrical elements of an apparatusfor detecting presence of fluid or change in phase of flowing fluidwithin a fluid circuit, including use of first and second thermistorsarrangeable in thermal communication with fluid within the fluidcircuit.

FIG. 10 is a line chart embodying dissolved gas saturation pressure (inPascals) versus time (in days) for simulations modeling gas releasedfrom folds during pressure dispense of fluid from seven different 200liter collapsible film-based container liners.

FIG. 11 is a line chart showing release of fold gas (milliliters) as afunction of time (minutes) for pressure dispensing of fluid from a firstfilm-based container liner with a single Z-fold configuration and from asecond film-based container liner with a double Z-fold configuration.

FIG. 12 is a line chart embodying dissolved gas saturation pressure (inPascals) versus time (in days) for simulations modeling gas releasedfrom folds during pressure dispense of fluid from (A) a 200 litercollapsible film-based container liner with zero headspace, (B) a 200liter collapsible film-based container liner with normal headspace, and(C) a first 200 liter collapsible film-based container liner with normalheadspace until a transition at .about.3.7 days, with admixing of fluiddispensed by the first liner with fluid dispensed by a second 200 literliner thereafter.

FIG. 13 is a schematic diagram showing interconnections between variouscomponents of a fluid dispensing system including first and second fluiddispensing apparatuses each having an associated pressure transducerarranged to monitor dispensed fluid pressure and having a ventablereservoir, with a common outlet receiving combined flows of fluid fromthe first and the second pressure dispensing apparatuses.

FIG. 14 is a schematic diagram showing interconnections between variouscomponents of a fluid dispensing system including first and second fluiddispensing apparatuses each having an associated scale arranged to sensecombined container/fluid weight and having a ventable reservoir, with acommon outlet receiving combined flows of fluid from the first and thesecond pressure dispensing apparatuses.

FIG. 15 is a schematic diagram showing interconnections between variouscomponents of a fluid dispensing system including first and second fluiddispensing apparatuses each having an associated flow meter and/or flowcontroller arranged to monitor dispensed fluid flow and having aventable reservoir, with a common outlet receiving combined flows offluid from the first and the second pressure dispensing apparatuses.

DETAILED DESCRIPTION

The present invention relates in certain aspects to improved dispensingsystems including capability to remove bubbles and entrained gas fromliquid and liquid-containing source materials subject to pressuredispensation. In a specific aspect, the invention relates to aliner-based liquid containment systems for storage and dispensing ofchemical reagents and compositions, e.g., high purity liquid reagentsand chemical mechanical polishing compositions used in the manufactureof microelectronic device products.

In the use of liner-based packages for storage and dispensing of fluidmaterials, wherein the liner is mounted in a rigid or semi-rigid outervessel, the dispensing operation may involve the flow of apressure-dispense gas into the vessel, exteriorly of the liner, so thatthe pressure exerted by the gas forces the liner to progressively becompacted so that the fluid material in the liner in turn is forced toflow out of the liner. The thus-dispensed fluid material may be flowedto piping, manifolding, through connectors, valves, etc. to a locus ofuse, e.g., a fluid-utilizing process tool.

Such liner-based liquid containment systems can be employed for storageand dispensing of chemical reagents and compositions of widely variedcharacter. Although the invention is hereafter described primarily withreference to storage and dispensing of liquid or liquid-containingcompositions for use in the manufacture of microelectronic deviceproducts, it will be appreciated that the utility of the invention isnot thus limited, but rather the invention extends to and encompasses awide variety of other applications and contained materials.

Although the invention is discussed hereinafter with reference tospecific embodiments including various liner-based packages andcontainers, it will be appreciated that various of such embodiments,e.g., as directed to pressure-dispense arrangements or other features ofthe invention, may be practiced in liner-less package and containersystems.

The term “microelectronic device” as used herein refers to resist-coatedsemiconductor substrates, flat-panel displays, thin-film recordingheads, microelectromechanical systems (MEMS), and other advancedmicroelectronic components. The microelectronic device may includepatterned and/or blanketed silicon wafers, flat-panel display substratesor polymer substrates. Further, the microelectronic device may includemesoporous or microporous inorganic solids.

In liner packaging of liquids and liquid-containing compositions(hereafter referred to as liquid media), it is desirable to minimize theheadspace of the liquid medium in the liner. The headspace is the volumeof gas overlying the liquid medium in the liner.

The liner-based liquid media containment systems of the presentinvention have particular utility in application to liquid media used inthe manufacture of microelectronic device products. Additionally, suchsystems have utility in numerous other applications, including medicaland pharmaceutical products, building and construction materials, foodand beverage products, fossil fuels and oils, agriculture chemicals,etc., where liquid media or liquid materials require packaging.

As used herein, the term “zero headspace” in reference to fluid in aliner means that the liner is totally filled with liquid medium, andthat there is no volume of gas overlying liquid medium in the liner.

Correspondingly, the term “near zero headspace” as used herein inreference to fluid in a liner means that the liner is substantiallycompletely filled with liquid medium except for a very small volume ofgas overlying liquid medium in the liner, e.g., the volume of gas isless than 5% of the total volume of fluid in the liner, preferably beingless than 3% of the total volume of fluid, more preferably less than 2%of the total volume of fluid and most preferably, being less than 1% ofthe total volume of fluid (or, expressed another way, the volume ofliquid in the liner is greater than 95% of the total volume of theliner, preferably being more than 97% of such total volume, morepreferably more than 98% of such total volume, even more preferably morethan 99% of such total volume, and most preferably more than 99.9% ofsuch total volume).

The greater the volume of the headspace, the greater the likelihood thatthe overlying gas will become entrained and/or solubilized in the liquidmedium, since the liquid medium will be subjected to sloshing, splashingand translation in the liner, as well as impact of the liner against therigid surrounding container during transportation of the package. Thiscircumstance will in turn result in the formation of bubbles (e.g.,microbubbles) and particulates in the liquid medium, which degrade theliquid medium, and render it potentially unsuitable for its intendedpurpose. For this reason, headspace is desired to be minimized andpreferably eliminated (i.e., in a zero or near-zero headspaceconformation) with complete filling of the interior volume of the linerwith liquid medium at the point of use. The package has to be shippedwith some headspace gas in order to accommodate expansion of thecontained material during shipment (as a result of temperaturevariation). Desirable systems according to the present inventiontherefore are arranged to remove the headspace gas at near atmosphericconditions after the package is coupled to a tool via dispensing flowcircuitry. At atmospheric conditions, the gas is released from thechemical reagent and can easily be purged from the system beforedispense of liquid to the tool.

The package includes a dispensing port that is in communication with theliner for dispensing of material therefrom. The dispensing port in turnis coupled with a suitable dispensing assembly. The dispensing assemblycan take any of a variety of forms, e.g., an assembly including a probeor connector with a dip tube that contacts material in the liner andthrough which material is dispensed from the vessel. The package can bea large-scale package, wherein the liner has a capacity in a range offrom 1 to 2000 or more liters of material.

In a pressure dispense mode, the liner-based package can be coupled witha pressurized gas source, such as a pump, compressor, a compressed gastank, etc.

The dispensing assembly in one embodiment is adapted for coupling withflow circuitry, e.g., flow circuitry of a microelectronic devicemanufacturing facility using a chemical reagent supplied in the liner ofthe package. The semiconductor manufacturing reagent may be aphotoresist or other high-purity chemical reagent or specialty reagent.

In one embodiment, a liner may be formed from tubular stock material. Bythe use of a tubular stock, e.g., a blown tubular polymeric filmmaterial, heat seals and welded seams along the sides of the liner areavoided. The absence of side welded seams may be advantageous to betterwithstand forces and pressures that tend to stress the liner, relativeto liners formed of flat panels that are superimposed and heat-sealed attheir perimeter.

A liner preferably is a single-use, thin membrane liner, whereby it canbe removed after each use (e.g., when the container is depleted of theliquid contained therein) and replaced with a new, pre-cleaned liner toenable the reuse of the overall container. Such a liner is preferablyfree of components such as plasticizers, antioxidants, UV stabilizers,fillers, etc. that may be or become a source of contaminants, e.g., byleaching into the liquid contained in the liner, or by decomposing toyield degradation products that have greater diffusivity in the linerand that migrate to the surface and solubilize or otherwise becomecontaminants of the liquid in the liner.

Preferably, a substantially pure film is utilized for the liner, such asvirgin (additive-free) polyethylene film, virgin polytetrafluoroethylene(PTFE) film, or other suitable virgin polymeric material such aspolyvinylalcohol, polypropylene, polyurethane, polyvinylidene chloride,polyvinylchloride, polyacetal, polystyrene, polyacrylonitrile,polybutylene, etc. More generally, the liner may be formed of laminates,co-extrusions, overmold extrusion, composites, copolymers and materialblends, with or without metallization and foil.

The thickness of the liner material can be any suitable thickness, e.g.,in a range from about 1 mils (0.001 inch) to about 120 mils (0.120inch). In one embodiment, the liner has a thickness of 20 mils (0.020inch).

The liner can be formed in any suitable manner, through use of one ormore sheets of film or other material that may be sealed (e.g., welded)along edges thereof. In one embodiment, multiple flat sheets aresuperimposed (stacked) and sealed along edges thereof to form a liner.One or more sheets may include a port or cap structure along an upperportion of a face thereof. In another one embodiment, tubular blowmolding is used with formation of an integral fill opening at an upperend of the vessel, which may be joined to a port or cap structure. Theliner thus may have an opening for coupling of the liner to a suitableconnector for fill or dispense operations involving respectiveintroduction or discharge of fluid. Such opening may be reinforced withstructure and termed a “fitment.” A fitment typically includes alaterally extending flange portion to which thin film is joined, and atubular portion extending in a direction substantially perpendicular tothe flange portion. A liner fitment may mate with or otherwise contact acontainer port, container cap or closure, or other suitable structure. Acap or closure may also be arranged to couple with a diptube forintroduction or dispensation of fluid.

In one embodiment, a rigid or substantially rigid collapsible liner isused. As used herein, the terms “rigid” or “substantially rigid,” inaddition to any standard dictionary definitions, are meant to alsoinclude the characteristic of an object or material to substantiallyhold its shape and/or volume when in an environment of a first pressure,but wherein the shape and/or volume may be altered in an environment ofincreased or decreased pressure. The amount of increased or decreasedpressure needed to alter the shape and/or volume of the object ormaterial may depend on the application desired for the material orobject and may vary from application to application. In one embodiment,at least a portion of a rigid or substantially rigid collapsible lineris rigid, and at least a portion of the liner is subject to collapseunder pressure dispensing conditions by application of a pressurizedfluid to or against at least a portion of such a liner. In oneembodiment, a rigid or substantially rigid collapsible liner may befabricated of material of sufficient thickness and composition for theliner to be self-supporting when filled with liquid. A rigid orsubstantially rigid collapsible liner may be of single-wall ormulti-wall character, and preferably comprises polymeric materials.Laminated composites of multiple layers of polymeric materials and/orother materials (e.g., laminated by application of heat and/or pressure)may be used. A rigid or substantially rigid collapsible liner may beformed by any one or more suitable lamination, extrusion, molding,shaping, and welding steps. A rigid or substantially rigid collapsibleliner preferably has a substantially rigid opening or port integrallyformed with the liner, thus avoiding the need for a separate fitment tobe affixed to the liner by welding or other sealing methods. Dispensingassemblies and dispensing apparatuses as disclosed herein may be usedwith rigid or substantially rigid collapsible liners.

A liner may include two ports or fitments in a top portion thereof,although single port liners, or alternatively liners having more thantwo ports, can be usefully employed in the broad practice of the presentinvention. A collapsible liner may be disposed in a substantially rigidhousing or overpack, which can be of a generally rectangularparallelepiped shape to promote stackabilty, with manual handlingopenings to enable the container to be manually grasped, and physicallylifted or otherwise transported in use of the container. Alternatively,the overpack can be of a cylindrical form, or of any other suitableshape or conformation. A generally rigid housing may also includeoverpack lid that is leak-tightly joined to walls of the housing, tobound an interior space containing the liner. An interstitial spaceprovided between the liner and overpack container may be in fluidcommunication with a pressurized gas source, such that addition ofpressurized gas to the interstitial space compresses the liner to causeliquid to be expelled from the liner.

A pressure dispense package as disclosed herein may be coupled to aprocess tool in a microelectronic product manufacturing facility. Such atool may, for example, comprise a spin coater for applying photoresistto a wafer, with the dispensed liquid constituting a suitablephotoresist material. The tool alternatively can be of any suitable typeadapted for utilizing a specified chemical reagent dispensed from thepressure dispense container. Liquid chemical reagents can therefore bedispensed for use in the microelectronic product manufacturing facilityfrom one or more liner-based packages to yield a microelectronic producte.g., a flat panel display or a semiconductor wafer incorporatingintegrated circuitry.

A liner advantageously is formed of a film material of appropriatethickness to be flexible and collapsible in character. In oneembodiment, the liner is compressible such that its interior volume maybe reduced to about 10% or less of the rated fill volume, i.e., thevolume of liquid able to be contained in the liner when same is fullyfilled in the housing 14. In various embodiments, the interior volume ofa liner may be compressible to about 0.25% or less of rated fill volume,e.g., less than 10 milliliters in a 4000 milliliter package, or about0.05% or less (10 mL or less remaining in a 19 L package), or 0.005% orless (10 mL or less remaining in a 200 L package). Preferred linermaterials are sufficiently pliable to allow for folding or compressingof the liner during shipment as a replacement unit. The liner preferablyis of a composition and character that is resistant to particle andmicrobubble formation when liquid is contained in the liner, that issufficient flexible to allow the liquid to expand and contract due totemperature and pressure changes and that is effective to maintainpurity for the specific end use application in which the liquid is to beemployed, e.g., in semiconductor manufacturing or other highpurity-critical liquid supply application.

For semiconductor manufacturing applications, the liquid contained inthe liner of a pressure dispensing container as disclosed herein shouldhave less than 75 particles/milliliter (more preferably less than 50,still more preferably less than 35, and more preferably less than 20particles/milliliter), of particles having a diameter of 0.20 microns orlarger, at the point of fill of the liner, and the liner should haveless than 30 (more preferably less than 15) parts per billion totalorganic carbon (TOC) in the liquid, with less than 10 parts per trillionmetal extractable levels per critical elements, such as calcium, cobalt,copper, chromium, iron, molybdenum, manganese, sodium, nickel, andtungsten, and with less than 150 parts per trillion iron and copperextractable levels per element for liner containment of hydrogenfluoride, hydrogen peroxide and ammonium hydroxide, consistent with thespecifications set out in the Semiconductor Industry Association,International Technology Roadmap for Semiconductors (SIA, ITRS) 1999Edition.

One aspect of the invention contemplates headspace removal from thecontainer so that the container has a zero or near-zero headspace. Aconnector of appropriate type is employed for coupling with thecontainer to enable dispensing operation to be conducted. The flowcircuitry coupled with the connector can be of any suitable type,including for example, solenoid valves, or high purity liquid manifoldvalves, as well as pressure regulators, e.g., of a current to pressurecontrolled type.

The foregoing system allows the headspace gas to be dispensed to areservoir that is “on-line” (active in the dispensing flow circuitry)and dispensing to a downstream process tool, or other locus of use. Theheadspace gas can also be dumped to a drain or other disposition couldbe made of such gas. Each of the multiple containers can be arrangedwith a dedicated reservoir, so as to allow headspace gas removal,separate from the system.

The above-described system can be coupled to existing equipment toimplement full control over chemical dispense by the downstream tool orother dispensed material-utilizing apparatus or process. The system canbe arranged to supply dispensed material to the inlet valves of areservoir, and be in a ready state when material is requested by thedownstream process equipment. This minimizes any changeover period whilemaximizing chemical utilization.

Headspace removal can utilize a sensor that detects liquid media in atube or in a reservoir. Components of the system described above can beused for stand-alone or retrofit systems, based on existing installationand facility requirements.

Referring to FIG. 2, in one embodiment a connector 100 for use with apressure dispense apparatus includes a gas extraction conduit 135 and aliquid extraction conduit 125 that are independent and distinct from oneanother. The connector 100 includes an upper body structure 101 to whicha gas vent valve 139 and a liquid dispensing valve 129 are fixed, toregulate flow through a gas outlet port 138 and a liquid outlet port128, respectively. The upper body structure 101 includes a pressuretransducer 119 in sensory communication with the liquid extractionconduit 125. One or more additional sensor(s) 155 may also be associatedwith the upper body structure 101 in sensory communication with eitheror both of the gas extraction conduit 135 and the liquid extractionconduit 125. Examples of types of sensors that may be employed as thesensor(s) 155 include level sensors, capacitive sensors, opticalsensors, chemical-specific presence and/or concentration sensors,pressure sensors, particle counters, temperature sensing elements, andflow metering elements, which may be operatively coupled to one or moresignal processing elements. Disposed below the upper body structure 101is an intermediate body structure 102 through which the gas extractionconduit 135 and the liquid extraction conduit 125 are defined. Theintermediate body structure 102 may be cylindrical in shape and haveassociated circumferential sealing elements 112, 113, which may be inthe form of O-rings, for mating with a corresponding bore or portion ofa dispensing assembly (described hereinafter). A lower opening 130 ofthe gas extraction conduit 135 is arranged along a lower surface of theintermediate body structure 102. A lower body structure 103 (such as maybe suitable for mating with a liner fitment adapter or diptube coupler,described hereinafter) may have an additional circumferential sealingelement 111, and may extend further downward to define a lower end 120.

The lower end 120 may be arranged for mating with a diptube (not shown)inserted link to the interior of a pressure dispense container forextraction of liquid therefrom. The intermediate body structure 102 andlower body structure 103 in combination may be termed a probe.

By providing a gas extraction conduit 135 and a liquid extractionconduit 125 that are independent and distinct within a unitary connector100, and eliminating presence of a reservoir, the connector illustratedin FIG. 2 differs from the connector including a reservoir and a commongas/liquid conduit as disclosed in International Patent ApplicationPublication No. WO/2007/146892 (“the '892 publication”) mentionedhereinabove. The connector 100 shown in the accompanying FIG. 2 repliesupon primary separation of bubbles (gas) and liquid within the pressuredispense package to which the connector 100 is affixed, rather thangas/liquid phase separation within an in-connector reservoir. If aliquid extraction opening (e.g., at the end of a diptube) exposed to theinterior volume of a pressure dispense container is arranged below a gasextraction opening exposed to the same interior volume, then gas may beextracted from the interior volume (i.e., via the gas extraction conduit135 and gas outlet port 138) before and/or during extraction of liquidfrom the interior volume (via the liquid extraction conduit 125 andliquid outlet port 128). A gas extraction opening exposed to theinterior of a pressure dispense container is preferably disposed at alevel above a liquid extraction opening exposed to the interior of thecontainer. Presence of independent extraction openings for liquid andgas permits continued flow of liquid through a connector of aliner-based pressure dispense assembly even if the liner should rupture,if the diptube extends to the bottom of a liner (or suitable container).Additionally, relative to the diptube disclosed in the '892 publication(which included two ports with one at the top portion above the diptubeand another at the bottom of the diptube), a diptube as disclosed hereineliminates the port at the top of the diptube so that even if a linershould leak, only liquid (without pressurization gas) air can bewithdrawn by the diptube. Moreover, elimination of an in-connectorreservoir (i.e., as disclosed in the '892 publication) significantlyreduces the overall size of the connector 100, and also avoids anylimitation associated with dispensing liquids of high viscosities and/orat high flow rates, in which gravimetric phase separation in the smallconfines of an in-connector reservoir may be too slow to preventcarryover of gas bubbles in a liquid outlet stream.

Referring to FIG. 3, in one embodiment a liquid delivery system for usewith a pressure dispense container may include a reservoir-based gasseparation device 180 that is distinct from and disposed downstream of aconnector (such as the connector 100 illustrated in FIG. 2) for use withthe pressure dispense container. The separation device 180 includes areservoir body 190 defining a liquid inlet port 195, a liquid outletport 196, a gas outlet port 197, and a sensor port 198. Reservoir bodiesof various types and including various filtration media consistent incharacter to the device 180 (but lacking any pressure transducer) arecommercially available from Mykrolis Corporation (Billerica, Mass.,USA). In FIG. 3, each of the liquid outlet port 196 and the gas outletport 197 may have an associated flow control element (e.g., valve) 186,187 to control or regulate flow through the respective port 196, 197.The reservoir body 190 defines an interior volume containing afiltration medium 191 adapted to permit passage of liquid but preventpassage of bubbles. The filtration medium 191 may include, for example,any one or more of a mesh, packed or porous media, a membrane, and aspunbonded material (e.g., spunbonded polyolefin). Multiple types offiltration media may be used for different or complementary purposes,and may be disposed in series. For example, a first filtration mediatype and/or porosity may be used to capture particulate material, asecond filtration media type and/or porosity may be used to preventpassage of gas bubbles of a specified first (e.g., larger) size, andthird filtration media type and/or porosity may be used to preventpassage of gas bubbles of a specified second (e.g., smaller) size.Selection of appropriate filtration media may be dependent uponproperties of the fluid to be dispensed and operating conditionsthereof; such selection is known to one skilled in the art. Multiplefilter bodies each having different filtration media from one anothermay be disposed in series. Each filter is preferably removable andreplaceable, such as with a dedicated fitting or housing adapted toreceive a replacement filter element.

In operation, fluid is supplied to the reservoir-based gas separationdevice 180 through a liquid supply line. Such fluid may include liquidhaving entrained bubbles and/or particles. The fluid enters the interior192 of the reservoir body 190. In one embodiment, liquid is permitted topass through the filtration medium 191, but gas bubbles within the fluidis not. Gas bubbles may accumulate along the exterior of the filtrationmedium 191, and then flow toward the gas outlet port 197 to exit thedevice 180. The gas control element 187 may be closed for extendedperiods while the liquid control element 186 remains open, to preventthe liquid from escaping through the gas control element 187. The gascontrol element 187 may be periodically opened to “burp” or otherwisevent gas that is accumulated within the reservoir interior 192, eitherwhile the liquid control element 186 remains open, or when the liquidcontrol element 186 is closed.

A pressure transducer 199A is in sensory communication with the interiorvolume 192 through the sensor port 198 and is arranged to generate anoutput signal indicative of pressure within such interior volume 192. Anassociated controller (not shown) may be arranged and used to controlflow of fluid (e.g., the fluid stream supplied to the reservoir body190, a liquid stream exiting the reservoir body, and/or a gas streamexiting the reservoir body) responsive to the output signal. In oneembodiment, the pressure transducer 199A may be used to sense pressuredroop of the dispense fluid as indicative of a condition of exhaustionor near exhaustion of fluid within the pressure dispense package. In oneembodiment, the pressure transducer 199A may be used to send an elevatedback pressure condition within the reservoir body 190, as indicative ofpotential clogging of the filtration medium 191 and/or accumulation ofexcess gas within the interior volume 192, so as to trigger appropriatealarms and/or remedial action. A level sensor 199B (e.g., capacitive) isalso provided with the reservoir-based gas separation device 180, andmay be used to sense liquid level within the interior 192 of thereservoir body 190. Operation of a pressure dispense container disposedupstream of the reservoir-based gas separation device 180, and/oroperation of the reservoir-based gas separation device 180 itself, maybe controlled responsive to an output signal of the pressure transducer199A and/or an output signal of the level sensor 199B. If liquid levelwithin the interior 192 of the reservoir body 192 drops too low, asdetected by the level sensor 199B, then such condition may be used totrigger venting of gas from the interior 192 using the gas controlelement 187 to provide automatic gas venting utility.

In one embodiment, either of the pressure transducer 199A and/or levelsensor 199B may be substituted or supplemented with at least one othersensor. Examples of types of sensors that may be employed as thesensor(s) 199A or 199B include optical sensors, chemical-specificpresence and/or concentration sensors, particle counters, flow meteringelements (e.g., a coriolis-type sensor), and temperature sensors. A flowmetering element may be embodied in a mass flow controller. Such othersensor(s) may be connected to the reservoir body 190 via an availableport 198, or may be disposed in a flow-through relationship, such asin-line with the fluid inlet port 195, the liquid outlet port 186,and/or the gas outlet port 187. Signals from the one or more othersensor(s) may also be used to control operation of a pressure dispensecontainer disposed upstream of the reservoir-based gas separation device180, and/or operation of the reservoir-based gas separation device 180itself.

FIGS. 4A-4B illustrate a specific arrangement of a dispensing assembly200 including a connector 270, a liner fitment adapter 250, and diptube230 for a pressure dispense package according to one embodiment, withFIG. 4B further including schematic illustrations of downstream flowcontrol components. The liner fitment adapter 250 is arranged forintermediate connection between the connector 270 and a liner fitment(such as shown in FIGS. 6A and 7A). Referring to FIG. 4A, the connector270 includes a body structure 201, a downwardly extending probe portion270A, a liquid outlet port 238 in fluid communication with a liquidextraction conduit 272, a gas outlet port 228 in fluid communicationwith a gas extraction conduit 279, and a pressurization gas inletarranged to supply gas to a pressurization gas conduit. The liquidextraction conduit 272 terminates at a lower end 271 of the connector270. The connector 270 may include an optional pressure sensor arrangedto sense pressure of gas supplied to the interstitial volume between theliner and the container. Circumferential sealing elements 274B, 275B,276B may be provided along lower portions of the connector 270 topromote sealing engagement of the connector 270 with an upper portion260 of a longitudinal bore defined in the liner fitment adapter 250. Theterm “longitudinal” as used in this context refers to a directiongenerally along or near a vertical axis when the fitment adapter isplaced upright. When the connector 270 is inserted into an upper portion260 of the longitudinal bore of the liner fitment adapter, sealingelements 275B, 274B of connector 270 are disposed above and below,respectively, at least one lateral gas passage 259 defined through theliner fitment adapter 250, and the liquid extraction conduit 272 of theconnector 270 is aligned with a central portion 255 and a lower portion252 of the longitudinal bore to enable fluid communication with thediptube 230. The term “lateral” as used in this context refers to adirection having a radial component departing from a substantiallylongitudinal direction. For example, the lateral gas passage 259 may beorthogonal to a longitudinal axis through the liner fitment adapter 250,or it may be angled to include change in both horizontal and verticalcomponents. The diptube 230 is insertable into the lower portion 252 ofthe longitudinal bore along a lower edge 251 of the liner fitmentadapter 250. The lateral gas passage 259, which includes an openingexposed to the interior volume of a liner of a pressure dispensepackage, is in fluid communication with the gas extraction conduit 279.A laterally protruding edge 261 is provided along an upper portion ofthe liner fitment adapter 250. Below the laterally protruding edge 261,a circumferential sealing element 266 (e.g., an O-ring) is disposed in agroove 265A to promote sealing between the fitment adapter 250 and aliner fitment or other component (not shown).

FIG. 4B shows the same dispensing assembly 200 as shown in FIG. 4A, butwith addition of a downstream flow control and sensing assembly 240including a liquid outlet line 246 having an associated pressuretransducer 245, a liquid flow control element 244, and a bubble sensor249 arranged to generate an output signal indicative of presence ofbubbles in liquid dispensed from the pressure dispense package. The flowcontrol and sensing assembly 240 also includes a gas outlet line 241having a bubble sensor and/or liquid sensor 242 and a gas flow controlelement 243. The flow control and sensing assembly 240 may include acontroller (not shown) to receive inputs from any of various sensorsdisposed in the assembly 240, associated with the dispensing assembly200, and/or associated with a process disposed further downstream of theflow control and sensing assembly 240. The pressure transducer 245 maybe utilized to sense pressure droop of the dispense fluid as indicativeof a condition of exhaustion or near exhaustion of fluid within thepressure dispense package, with an output signal of the pressuretransducer 245 being useable to effect automatic switchover ofdispensing from one pressure dispense container to another, to actuatean alarm condition, or take any other appropriate action. The bubblesensor 249 arranged in the liquid outlet line 246 may be used to detectwhether bubbles are being dispensed in the liquid line, and if so, tostop dispensing. The bubble sensor and/or liquid sensor 242 arranged inthe gas outlet line 241 may be used to sense a condition indicate ofliquid presence in the gas outlet line 241, and if so, to stop passageof fluid through the gas outlet line 241. The foregoing sensors may besubstituted or supplemented with one or more sensors of various types asdisclosed herein, such as (but not limited to) level sensors, capacitivesensors, optical sensors, chemical-specific presence and/orconcentration sensors, pressure sensors, particle counters, and flowmetering elements. Headspace gas may be vented through the gas outletline 241 just before or at the beginning of pressure dispensation ofliquid from a pressure dispense container, with the gas flow controlelement 243 (e.g., a valve) being operable to selectively trigger suchventing. Flow through the gas outlet line may be blocked during liquiddispensing operation while liquid is flowing through the liquid outletline 246.

FIGS. 5A-5C illustrate a liner fitment adapter 350 similar in characterto the liner fitment adapter 250 illustrated in FIGS. 4A-4B. The maleinner portion 350A of the fitment adapter 350 includes an upper surface361 having a flared edge 362, with an annular recess 363 extending belowthe upper surface 361. Below the flared edge 362, a circumferentialgroove 366 is provided to receive a sealing element such as an O-ring(not shown) to promote sealing between the fitment adapter 350 and aliner fitment or other component (not shown).

As shown in FIG. 5B, the fitment adapter 350 may be fabricated in twoparts, including a cup-like female outer portion 350B having a wall 357,and a male inner portion 350A arranged for insertion into the outerportion 350B. The female outer portion 350B defines a cavity 354 andnotches 353 that are arranged to receive lateral tubes 359A defininglateral gas passages 359 of the male inner portion 350A. The femaleouter portion 350B has a lower end 351B defining a bore 358 arranged toreceive a protruding lower end 351A of the male inner portion 350A, withdetent and recess elements defined in the portions 350A, 350B forretention of such portions. The male inner portion 350A defines alongitudinal bore including an upper portion 360 (defined in part by anupwardly protruding tubular segment 360A), and intermediate bore portion355, and a lower bore portion 352 that extends to a lower edge 351B ofthe male portion 350A of the fitment adapter 350. The bore portions 360,355, 352 are preferably coaxial but may have different diametersrelative to one another; as shown. The intermediate portion 355 may havea small diameter than each of the upper portion 360 and the lowerportion 352 to serve as a travel stop so as to prevent insertion ofeither a connector or dip tube too far into the liner fitment adapter350. The lower bore portion 352 may optionally define at least onehelical compression feature (not shown) arranged to compressively retaina diptube (not shown) inserted into the lower portion 352 of thelongitudinal bore. The upper bore portion 360 is arranged to receive aportion of a connector (such as the connector 270 shown in FIGS. 4A-4B).The lateral gas passage 359 as illustrated in FIG. 5C is substantiallyorthogonal (perpendicular) to the upper portion 360 of the longitudinalbore. In operation of a dispensing assembly including the liner fitmentadapter 350, the lateral gas passage 359 is preferably in fluidcommunication with a gas extraction conduit when a connector is insertedinto the upper bore portion 360.

FIG. 6A illustrates a dispensing apparatus 300 including a connector370, a closure 310, a liner fitment retainer 315, and a liner fitmentadapter 350, arranged for use with a pressure dispense package. A linerfitment (not shown) would be disposed between the fitment retainer 315and liner fitment adapter 350. The connector 370 includes a bodystructure 301, a downwardly extending probe portion 370A, a liquidoutlet port 328 in fluid communication with a liquid extraction conduit372, a gas outlet port 338 in fluid communication with a gas extractionconduit 379, and a pressurization gas inlet 348 in fluid communicationwith a pressurization gas conduit 347. The liquid extraction conduit 372terminates at a lower end 371 of the connector 370. The connector 370may include an optional pressure sensor, which may be arranged to sensepressure in the interstitial space between the liner and the overpackcontainer. Various circumferential grooves (e.g., grooves 375A, 376A,377A) arranged to retain circumferential sealing elements (e.g., sealingelements 374B, 377B) such a O-rings may be provided along portions ofthe connector 370 to promote sealing engagement of the connector 370with an upper portion 360 of a longitudinal bore defined in the linerfitment adapter 350. When the connector 370 is inserted into an upperportion 360 of the longitudinal bore of the liner fitment adapter 350,sealing elements (e.g., as installed in grooves 375A, 376A) of theconnector 370 are disposed above and below, respectively, a lateral gaspassage 359 defined through the liner fitment adapter 350, and theliquid extraction conduit 372 of the connector 370 is aligned with acentral portion 355 and a lower portion 352 of the longitudinal bore toenable fluid communication with a diptube (such as diptube 330illustrated in FIG. 6B) insertable into the lower portion 352 of thelongitudinal bore along the lower edge 351 of the liner fitment adapter350. The lateral gas passage 359 as illustrated in FIG. 6A issubstantially orthogonal (perpendicular) to the upper portion 360 of thelongitudinal bore defined in the liner fitment adapter 350, and thelateral gas passage 359 being in fluid communication with the gasextraction conduit 379 (by way of a lateral segment 378 defined in theconnector 372) when the connector 370 is inserted into the fitmentadapter 350. A laterally protruding edge is provided along an upperportion of the liner fitment adapter 350. Below the laterally protrudingedge 361, a circumferential groove 366 is provided to receive acircumferential sealing element (e.g., an O-ring) to promote sealingbetween the fitment adapter 350 and the liner fitment retainer 315 orother associated components.

Arranged for placement adjacent to the liner fitment adapter 350 is aliner fitment (not shown) adapted to be joined to a collapsible liner(not shown). Disposed above the liner fitment retainer 315 and linerfitment adapter 350 is a closure 310 for a pressure dispensing vesselsuch as an overpack container (not shown), with the closure 310including a female threaded surface 311 arranged for mating with acorresponding male threaded neck (not shown) of a pressure dispensingvessel. The closure 310 has an associated male threaded neck 312 thatextends upward to receive a threaded socket 302 along a lower portion ofa connector body 301 A breakseal 305 is disposed within or adjacent tothe threaded neck 312, and preferably includes a rupturable membranethat maintains sealing conditions within a pressure dispense packageuntil the connector 370 is inserted through the breakseal 305 to matewith the liner fitment adapter 350. When the connector 370 is insertedinto the liner fitment adapter 350, fluidic connections aresimultaneously made between (a) the gas extraction conduit 379 and theinterior volume of a liner (not shown) mounted to the liner fitment, (b)the liquid extraction conduit 372 and the interior volume of the liner,and (c) the pressurization gas conduit (not shown) and an interstitialspace between an overpack container (not shown) and the liner.Establishment of simultaneous connections with a single connectorinsertion step promotes user convenience and eliminates possibility offaulty connection, and presence of a single opening in a liner minimizespotential leakage paths.

A diptube 330 suitable for use with the dispensing assembly 300 is shownin FIG. 6B. The diptube, which includes a central bore arranged toconduct fluid, includes a straight upper end 332 and a lower end 331including a lateral opening 333 and a bottom bore opening (not shown).Presence of both a lateral bore opening 333 and a bottom bore openingreduces likelihood that liquid flow from a liner to the diptube 330 willbe occluded (i.e., both vertically and laterally) by collapse of such aliner during pressure dispensing operation. The diptube 330 have astraight upper end 332 is arranged to be press-fit into the lowerportion 352 of the longitudinal bore of the liner fitment adapter 350(shown in FIG. 6A). Since the intermediate portion 352 of thelongitudinal bore of the liner fitment adapter 350 has a smallerdiameter than the diptube 330, the diptube 330 should be fitted into thelower portion 352 of the longitudinal bore of the liner fitment adapter350 before the liner fitment adapter 350 is inserted into a pressuredispense container, and before the connector 370 is inserted into upperportion 360 of the longitudinal bore of the liner fitment adapter 350.

FIG. 7A shows a dispensing apparatus 400 that is similar in manyrespects to the dispensing apparatus of FIG. 6A, but with a differentliner fitment adapter 450 that is arranged for use with a differentdiptube (i.e., the diptube 430 illustrated in FIG. 7B). The dispensingapparatus 400 including a connector 470, a closure 410, a liner fitmentretainer 415, and a liner fitment adapter 451, arranged for use with apressure dispense package. The connector 470 includes a body structure401, a downwardly extending probe portion 470A, a liquid outlet port 428in fluid communication with a liquid extraction conduit 472, a gasoutlet port 438 in fluid communication with a gas extraction conduit479, and a pressurization gas inlet 448 in fluid communication with apressurization gas conduit (not shown). The liquid extraction conduit472 terminates at a lower end 471 of the connector 470. The connector470 may include an optional pressure sensor, which may have anassociated pressure sensing line in fluid communication with theinterstitial space between the liner and the overpack container. Variouscircumferential grooves (e.g., grooves 475A, 476A, 477A) arranged toretain circumferential sealing elements (e.g., sealing elements 474B,477B) such a O-rings may be provided along portions of the connector 470to promote sealing engagement of the connector 470 with an upper portion460 of a longitudinal bore 460 in the liner fitment adapter 450. Whenthe connector 470 is inserted into the upper portion 460 of thelongitudinal bore, sealing elements (e.g., as installed in grooves 475A,476A) of the connector 470 are disposed above and below, respectively, alateral gas passage (not shown) defined through the liner fitmentadapter 450 to extend into the longitudinal bore, and in fluidcommunication with a lateral segment 478 and gas extraction conduit 479defined in the connector 470. Grooves 476A, 477A may include sealingelements (not shown) arranged to engage the upper portion 460 of thelongitudinal bore of the liner fitment adapter 450.

When the connector 470 is inserted into the liner fitment adapter 450,the lower end 471 of the connector 470 (i.e., opening into liquidextraction conduit 472) engages a coupler 490 disposed within thelongitudinal bore, with a first sealing element 474B and an additionalsealing element (not shown) disposed in a circumferential groove 475A inthe coupler 490 being arranged to engage an upper recess of the coupler490. The coupler 490 includes a body 471 with a flared exterior portion495 arranged to abut a shoulder 461 of the longitudinal bore 460. Ribs497 arranged along an exterior surface 493 of the coupler 490 areprovided to support and locate the fitment adapter 450. Gaps (not shown)allow passage of gas past the ribs 497. The coupler 490 also defines aliquid conduit 495 in fluid communication with the liquid extractionconduit 472 to enable fluid communication with a diptube (such asdiptube 430 illustrated in FIG. 7B) insertable into a lower portion ofthe longitudinal bore 460 to mate with a lower end 491 of the coupler490. An outer surface 493 of the coupler 490 preferably engages an innersurface of a flared upper portion 432 of a diptube 430, as illustratedin FIG. 7B. A diptube 430 (illustrated in FIG. 7B) arranged for use withthe dispensing assembly 400 includes an upper end 432 with a flaredportion 435 tapering down at a shoulder 434 to a tubular body thatterminates at a lower end 431, with a hollow bore extending from thelower end 431 to the upper end 432. A lateral opening 433 into the boreis defined near the lower end 431. The lower end 431 of the diptube 430is insertable into a liner of liner-based pressure dispense package,with the lower end 431 of the diptube 430 serving as a liquid extractionopening exposed to the interior volume of the liner.

Referring to FIGS. 7A and 7B in combination, in one embodiment a coupler490 and diptube 430 are affixed to the lower end 471 of the connector470, and the combined subassembly (including diptube 430, coupler 490,and connector 470) are inserted together through a breakseal 405 andinto the longitudinal bore (e.g., through upper portion 460 and intolower portion 455 of the longitudinal bore) of the liner fitment adapter450, with the diptube 430 extending through a lower opening 456 definedin the liner fitment adapter 450. A retaining or sealing element 456Amay be disposed adjacent to the lower opening 456 to provide structuralsupport and/or sealing engagement for the diptube 430. The ability toinsert the diptube 430 and coupler 490 from above (i.e., from outsidethe pressure dispense package) permits the end user to select a diptube430 of appropriate dimensions for use with a specific pressure dispensecontainer. After insertion of the diptube 430, coupler 490, andconnector 470 into the longitudinal bore, removal of the coupler 490 anddiptube 430 may be inhibited by presence of the shoulder 461 thatdivides the upper portion 460 and lower portion 455 of the longitudinalbore. If the shoulder 461 is minimized, then the diptube 430 and coupler430 may be removed from above from the dispensing assembly.

In another embodiment, the coupler 490 and diptube 430 may be positionedwithin the longitudinal bore of the liner fitment adapter 450 prior toinsertion of the connector 470 past the breakseal 405 and into the upperportion 460 of the longitudinal bore.

Continuing to refer to FIG. 7A, a laterally protruding edge 461 isprovided along an upper portion of the liner fitment adapter 450. Belowthe laterally protruding edge 461, grooves 466 are provided to receive acircumferential sealing element (e.g., an O-ring) to promote retentionbetween the fitment adapter 450 and a liner fitment or other associatedcomponents. Adjacent to the liner fitment adapter 450 a liner fitment(not shown) and collapsible liner (not shown) may be provided.

Disposed above the liner fitment retainer 415 and liner fitment adapter450 is a closure 410 for a pressure dispensing vessel such as anoverpack container (not shown), with the closure 410 including a femalethreaded surface 411 arranged for mating with a corresponding malethreaded neck (not shown) of a pressure dispensing vessel. The closure410 has an associated male threaded neck 412 that extends upward toreceive a threaded socket 402 along a lower portion of a connector body401. A breakseal 405 is disposed within or adjacent to the threaded neck412, and preferably includes a rupturable membrane that maintainssealing conditions within a pressure dispense package one or morecomponents (e.g., the connector 470) are inserted through the breakseal405 to mate with the liner fitment adapter 450. When the connector 470is inserted into the liner fitment adapter 470, fluidic connections aresimultaneously made between (a) the gas extraction conduit 479 and theinterior volume of a liner (not shown) mounted to a liner fitment, (b)the liquid extraction conduit 472 and the interior volume of the liner,and (c) the pressurization gas conduit and an interstitial space betweenan overpack container (not shown) and the liner.

In certain embodiments, multiple temperature sensing elements may beused to detect presence of fluid or change in phase of flowing fluidwithin a fluid circuit. Use of temperature sensors for fluid detectionmay be advantageously employed for sensing presence or change in phaseof highly opaque liquids (e.g., pigmented color filter materials andused for coating flat panels in the manufacture of display monitors, andsimilar fluids), since such fluids are generally not amenable to opticaldetection. Heat may be dissipated into a flowing fluid at a firstlocation, and a first sensing element may be arranged in sensorycommunication with the first heating element and the fluid, and adaptedto generate a first output signal correlative of temperature of thefirst heating element. In one embodiment, the first heating element andthe first sensing element may comprise a single (first) thermistordriven at a first current level sufficient for the first thermistor tobe self-heating. A second sensing element may be arranged in sensorycommunication with the fluid at a second location within the fluidcircuit, and adapted to generate a second sensing element output signalcorrelative of temperature of the fluid at the second location. In oneembodiment, the second sensing element comprises a second thermistordriven at a second current level that is substantially lower than thefirst current level. A signal processing element (e.g., including butnot limited to a comparator and an amplifier) may be arranged to receivethe first sensing element output signal and the second sensing elementoutput signal, and to determine presence of fluid or change in phase offlowing fluid within the fluid circuit based on comparison of the firstsensing element output signal and the second sensing element outputsignal. Other types of temperature sensing elements (e.g., including butnot limited to thermocouples and resistance temperature detectors) maybe used in conjunction with at least one separate heating element.

The foregoing apparatus is capable of sensing presence of liquid or gasdue to different heat capacities of fluids in liquid or gas phase. Afluid in liquid phase generally has a greater heat capacity than a fluidin gas phase. When a heating element (e.g., including a thermistor) issupplied with electric current at level that exceeds the ability of gasflowing over the heating element to dissipate such heat, then theheating element will exhibit self-heating, its temperature will rise,and such temperature is detectable with a first temperature sensor. Whenthe same heating element operating at the same electric current supplylevel is exposed to a liquid flowing over the heating element, however,the heating element may not exhibit self-heating if the flowing liquidis able to absorb such heat. A second temperature sensor in sensorycommunication with the fluid in the same fluid circuit is used fortemperature compensation. A difference in temperature between the firsttemperature sensor and the second temperature sensor is amplified andmeasured. Detection of a condition corresponding to a self-heating stateof the first temperature sensor indicates that the first temperaturesensor is exposed to a gas, whereas detection of a conditioncorresponding to a lack of self-heating state of the first temperaturesensor indicates that the first temperature sensor is exposed to aliquid. To account for possible variation in flow rate through the fluidcircuit with respect to time, a comparison between first and secondtemperature sensors may also be compensated with an output of anoptional flow rate sensor.

In one embodiment, various components of an apparatus to detect presenceof fluid or change in phase of flowing fluid within a fluid circuit (asdescribed above) may be integrated into a single apparatus, such as aconnector for a liner-based pressure dispensing container arranged toreceive pressurized gas from a gas source to exteriorly apply pressureto a liner for compression thereof, or an apparatus arranged to beplaced in a fluid circuit disposed downstream of a fluid dispensingcontainer. In one embodiment, the first sensing element and the secondsensing element are arranged in a first apparatus (e.g., a connector fora pressure dispense container) and the signal processing element isarranged in a second apparatus that is physically remote from the firstapparatus with appropriate electrical connections therebetween.

In one embodiment, an apparatus adapted to detect presence of fluid orchange in phase of flowing fluid within a fluid circuit utilizing firstand second temperature sensing elements is adapted to detect change inphase from gas phase to liquid phase of flowing fluid within a fluidcircuit (e.g., located downstream of a fluid dispensing container suchas a liner-based pressure dispense container).

In one embodiment, an apparatus adapted to detect presence of fluid orchange in phase of flowing fluid within a fluid circuit utilizing firstand second temperature sensing elements is adapted to detect presence orabsence of at least one gas bubble in flowing fluid within the fluidcircuit.

In one embodiment, an apparatus adapted to detect presence of fluid orchange in phase of flowing fluid within a fluid circuit utilizing firstand second temperature sensing elements is utilized in conjunction withat least one other sensing apparatus operating according to differentsensing principles (e.g., an optical sensor, a capacitive sensor, or thelike), and the signals of such different sensing apparatuses arecompared. Utilization of apparatuses operating according to differentsensing principles may provide increase reliability and reduce thepossibility for dispensing errors.

In one embodiment, a fluid dispensing system includes an apparatusadapted to detect presence of fluid or change in phase of flowing fluidwithin a fluid circuit utilizing first and second temperature sensingelements and a signal processing element arranged to compare outputs ofthe first and second temperature sensing elements. Such fluid dispensingsystem further includes a gas vent, a liquid receiving line in fluidcommunication with a process tool, and flow control element arranged toselectively admit fluid into the liquid receiving line, wherein thesystem is adapted to operate the flow control element to admit fluidinto the liquid receiving line responsive to receipt of a signal derivedfrom the signal processing element indicative of presence of liquidwithin the fluid circuit.

In one embodiment, a method for sensing presence of fluid or change inphase of flowing fluid within a fluid circuit utilizes a firstthermistor in sensory communication with the fluid at a first locationwithin the fluid circuit and utilizes a second thermistor in sensorycommunication with the fluid at a second location within the fluidcircuit. The first thermistor is driven at a first electrical currentlevel sufficient to cause self-heating of the first thermistor uponexposure of a sensing portion thereof to gas. The second thermistor isdriven at a second electrical current level that is substantially lowerthan the first current level. A first output signal of the firstthermistor and a second output signal of the second thermistor arecompared (e.g., using a signal processing element, such as may include acomparator and an amplifier) to determine presence of fluid or change inphase of flow fluid within the fluid circuit based on such comparison.In one embodiment, a flow control element is used to selectively control(i) venting of gas from the fluid circuit, and/or (ii) dispensation offluid from the fluid circuit to a process tool, and such flow controlelement is controlled responsive to said comparison of the first outputsignal to the second output signal.

In one embodiment, a fluid circuit is operatively connected to aliner-based pressure dispense container arranged to receive pressurizedgas from a gas source to exteriorly apply pressure to a liner forcompression thereof, and a method includes controlling dispensation offluid from the liner-based pressure dispense container to the fluidcircuit responsive to a comparison of a first output signal generated bya first temperature sensor to a second output signal generated by asecond temperature sensor, wherein the first temperature sensor includesor is associated with heating element arranged to dissipate heat intofluid within the fluid circuit.

FIG. 8 is a schematic illustrating interconnections between variouscomponents of a fluid dispensing system 500 including multipletemperature sensing elements 521, 522 and a signal processing element525 arranged to determine presence of fluid or change in phase offlowing fluid in a fluid circuit 530 based on comparison of outputs ofthe temperature sensing elements 521, 522. Fluid is dispensed into thefluid circuit 530 from a pressure dispense apparatus including an outercontainer 510 containing a collapsible liner 512 and arranged to receivepressurized gas into an interstitial space 511 between the outercontainer 510 and the liner 512 from a gas source 502 via a gas supplyline 503. When pressurized gas is supplied into the interstitial space511, such gas applies exterior pressure to the liner 512 for compressionthereof, to dispense fluid from the liner 512 into the fluid circuit530. The fluid circuit 530 may include a flow sensing element 523 tosense flow rate of fluid within the fluid circuit 530. First and secondtemperature sensing elements (e.g., thermistors) 521, 522 are arrangedin sensory communication with fluid in the fluid circuit 530. Thevarious sensing elements 521-523 are in communication with a signalprocessing element 525, which may also provide control functionality.The signal processing element 525 may comprise a microprocessor,discrete circuit elements, a programmable logic controller, and/or otherknown elements arranged to receive and process sensory inputs andprovide an output signal, optionally arranged to execute amachine-readable instructions such as software. The pressurized gassource 502 may be arranged to receive a signal from the signalprocessing element 525 for controlling or affecting dispensation offluid from the liner 512 into the fluid circuit 530. Downstream of thetemperature sensing elements 521, 522, at least one flow control element530 such as one or more valves is arranged to selectively admit fluid toa vent 531 (and/or waste receptacle) or to a process tool or other pointof use 532. A degasser 533 may be arranged upstream of the process toolor other point of use 532. The at least one flow control element 530 isarranged to receive a signal from the signal processing element 525 forautomatic operation thereof.

In operation of the fluid dispensing system 500, pressurized gas issupplied to the interstitial space 511 between the pressure dispensecontainer 510 and the liner 512 contained therein to compress the liner512 to cause fluid to be dispensed from the liner into the fluid circuit530. Fluid contained in the liner 512 may include headspace gas andliquid (e.g., a highly opaque liquid such as pigmented color filtermaterials or similar fluids), such that fluid dispensed into the fluidcircuit may initially be composed primarily of headspace gas. Flow rateof the fluid may be sensed by a flow sensing element 523, and a signalcorrelative of fluid flow rate may be supplied to the signal processingelement 525. One temperature sensing element 521 (e.g., thermistor) isdriven at an electric current sufficient to cause self-heating of thesensing element 521 in exposure to gas. A second sensing element 522(e.g., thermistor) is driven at a substantially lower electric currentthan the current supplied to the other sensing element 521, so that thesecond sensing element 522 does not experience self-heating in exposureto gas within the fluid circuit 530. The signal processing element 525receives and compares signals from the first and second sensing elements521, 522 to determine whether gas or liquid is present in the fluidcircuit 530. When gas is sensed in the fluid circuit 530, the signalprocessing element 525 generates a signal that is used by the at leastone flow control element 530 to admit fluid from the fluid circuit 530to a vent 531 or waste receptacle. Alternatively, when liquid is sensedin the fluid circuit 530 after initial venting of headspace gas, thismay signify that headspace gas has been exhausted and the system 500 isready for dispensing liquid to the process tool 532 or other point ofuse, and the flow control element 530 responds to a signal from thesignal processing element to admit liquid from the fluid circuit 530into the process tool 532 or other point of use. Such liquid may flowthrough an optional degasser 533 for reduction or removal of any gasdissolved or entrained in the liquid. Any one or more of variouscomponents of the system 500 (e.g., sensing element(s) 521-523, signalprocessing element(s) 525, and/or flow control element(s) 530) mayoptionally be arranged in or on a connector 515 adapted for mating withthe pressure dispense container 510. Such connector 515 may embody orcontain any one or more additional connector components and/or featuresas described previously herein.

FIG. 9 is a circuit diagram modeling electrical elements of an apparatusfor detecting presence of fluid or change in phase of flowing fluidwithin a fluid circuit, including use of first and second thermistorsarrangeable in thermal communication with fluid within the fluidcircuit. Thermistor R2 (e.g., as may be embodied in a Jameco 207483thermistor (Jameco Electronics, Belmont, Calif.) embodies a first ormain temperature sensing element, and is driven with an electric currentof 5.05 milliamperes. Characteristics of the Jameco 207483 thermistorare specified as −4.3%/.degree. C. and 6.5 mW/.degree. C. Given thecharacteristics of the thermistor R2, self-heating of about 3.8 degreesCelsius is expected in exposure of the thermistor R2 to air, but inliquid, such self-heating will be nearly zero due to the much higherheat capacity of the liquid as compared to air. Thermistor R3 (as maycomprise the same type as thermistor R2) is driven with an electriccurrent of 50 microamperes, and will have very little self heating inexposure to gas or liquid; this thermistor R3 is used to compensate thesignal from the other thermistor R2. The difference between outputsignals of the two thermistors R2, R3 is amplified using amplifier U3and measured. In the illustrated simulation, the expected change insignal between gas and liquid is 10% (i.e., about 900 mV in air, andabout 1000 mV in liquid), which difference is easily detectible withstandard circuit components. As indicated previously, temperaturesensing elements of types other than thermistors may be used.

As noted previously, while illustrative embodiments have been describedas including liner-based pressure dispense packages, aspects of thepresent invention may be applied to liner-less package and containersystems. In one embodiment, insertion of a connector into a dispensingassembly simultaneously makes fluidic connections between (a) a gasextraction conduit and a dispensing volume within a container; (b) aliquid extraction conduit and the dispensing volume within thecontainer, and (c) a pressurization gas conduit and a space to bepressurized within a pressure dispense vessel, with the gas extractionconduit, liquid extraction conduit, and pressurization gas conduit beingdistinct from one another.

In certain embodiments, negative effects of gas contacting sourcematerial (e.g., liquid) dispensed by a first pressure dispense apparatusbe reduced by detecting a condition correlative of dispensation of adesired amount of fluid from, or correlative of an approach to gassaturation of fluid dispensed by, the first pressure dispense apparatus,and responsively combining (e.g., diluting) the output of the firstpressure dispense apparatus with fluid dispensed by a second pressuredispense apparatus. The combined fluid stream may be supplied by adispensation conduit to a desired point of use, such as a tool forprocessing semiconductors or microelectronic devices. Such combinationof fluid streams from multiple pressure dispense apparatuses permits thegas saturation level of fluid (e.g., source material for semiconductorprocessing and/or microelectronic device processing) to be maintainedbelow acceptable levels. Various conditions that may be sensed (e.g.,utilizing one or more sensing elements) as one or more threshold(s) forcombining streams output by multiple pressure dispense apparatusesinclude (but are not limited to) pressure of fluid output by a pressuredispense apparatus, weight of fluid remaining within a pressure dispenseapparatus (or, conversely, weight of fluid dispensed by a pressuredispense apparatus), and/or totalized flow of fluid dispensed by apressure dispensed apparatus.

Preferably, the second pressure dispense apparatus contains less gas(and has a lower ratio of gas to source material (e.g., liquid)) thanthe first pressure dispense apparatus when the fluid streams output bythe first and second pressure dispense apparatuses are combined. Atleast one ventable reservoir is preferably provided to receive fluidfrom the first and second pressure dispense apparatuses, to permitseparation of gas and liquid upstream of an outlet to a process tool orother desired point of use of the source material (e.g., liquid). Incertain embodiments, each pressure dispense apparatus has a dedicatedventable reservoir associated therewith. Use of a dedicated ventablereservoir for each pressure dispense apparatus allows the effect andoperational performance of one pressure dispense apparatus to beseparated from another pressure dispense apparatus. Each ventablereservoir may include a liquid outlet, a gas outlet, a source material(e.g., liquid) inlet, and a headspace gas inlet, with a control valvepreferably associated with each inlet and outlet. A gas outlet may belocated above a liquid outlet to permit separation of gas and liquid tobe aided by gravity. A desired liquid level within a ventable reservoirmay be automatically maintained with outlet control valves operativelycoupled with sensors (of any suitable type, such as level sensors,capacitive sensors, conductivity sensors, optical sensors, etc.)arranged to sense presence and/or absence of source material atspecified levels within such a reservoir. Each ventable reservoirpermits at least periodic venting of gas, such as prior to dispensing ofliquid source material (e.g., for headspace removal) and/or duringdispensing of liquid source material. In one embodiment, a ventablereservoir comprises a filtration medium adapted to permit passage ofliquid but prevent passage of gas bubbles, such as described previouslyherein. In one embodiment, a ventable reservoir may be physicallyseparated from a pressure dispense container. In another embodiment, aventable reservoir may be mounted to a pressure dispense container, suchas by integration of a reservoir within a cap arranged to mate with sucha container.

Streams of fluid discharged by first and second pressure dispenseapparatuses may be combined in a tee, in a multi-port valve, or anyother suitable flow-combining structure. One or more static and/ordynamic mixers may be used to enhance uniformity of the resultingcombined flow. In one embodiment, fluids dispensed by first and secondpressure dispense apparatuses have the same composition (e.g., asidefrom presence of any headspace gas dissolved therein). In anotherembodiment, fluids dispensed by first and second pressure dispenseapparatuses have different compositions.

Streams of fluid discharged by first and second pressure dispenseapparatuses may be combined and/or adjusted in any desired proportions.In one embodiment, streams from first and second pressure dispenseapparatuses may be combined in roughly equal proportions. In certainembodiments, proportions of fluid in a combined stream including outputsof first and second pressure dispense apparatuses may be altered byadjusting relative dispense pressures of the perspective pressuredispense apparatuses, and/or through use of one or more control valvearranged to regulate flow of one or more fluid streams. In certainembodiments, proportions of fluid in a combined stream including outputsof first and second pressure dispense apparatuses are altered withrespect to time. For example, as a first pressure dispense apparatus isnearly depleted of source material (e.g., liquid) and a highconcentration of gas is present therein, an increasing percentage offluid discharged from a second pressure dispense apparatus may be mixedwith fluid discharge from the first pressure dispense apparatus tomaintain the combined fluid flow at an acceptably low gas saturationlevel. Proportions of constituent fluid in a combined fluid stream maybe adjusted responsive to output of one or more sensors, such as (butnot limited to) pressure sensors, weight scales, or flow sensors(including totalized flow sensors).

As the flow rate dispensed from the first pressure dispense apparatus isdecreased, the pressurized time for the first pressure dispenseapparatus is lengthened. During this lengthened time period, more gaswill be dissolved into the small amount of liquid left in the firstpressure dispense apparatus (or container thereof) before liquid thereinis fully depleted. Depending on the blending starting point, the gas inthe first pressure dispense apparatus will continue to be dissolved inthe source material (e.g., liquid) until a gas saturation condition isreached. One simple blending algorithm includes the assumption that allremaining source material in the first pressure dispense apparatus issaturated, and such material is blended appropriately with sourcematerial from another (e.g., second) pressure dispense apparatus toattain a resulting source material blend that is not saturated with gasunder pressure. Other blending algorithms may be employed. In oneembodiment, at least one sensor may be used to sense a conditionindicative of gas content of liquid remaining in (or liquid dispensedby) the first pressure dispense apparatus, optionally in combinationwith at least one sensor used to sense a condition indicative of gascontent of liquid within (or liquid dispensed by) a second pressuredispense apparatus, with signals from such sensor(s) being used tocontrol blending of streams of source material from the first and secondpressure dispense apparatuses. In one embodiment, a signal indicative ofgas content of at least one flow of source material is generated with amass flow sensor and a volumetric flow sensor (optionally corrected by atemperature sensor), with the quotient of mass divided by volume used todetermine density of the source material. A functional relationshipbetween density and gas content (or gas saturation condition) may bepredetermined empirically, and a measured density signal may be comparedto empirical data (or a mathematical function derived from empiricaldata), with such comparison being used to control blending of sourcematerial streams from different containers, and with the object ofgenerating a resulting (blended) source material stream that is notsaturated with gas (or maintains a gas content below a specifiedthreshold). In another embodiment, pressure sensing may be used tocontrol proportions of source material streams to produce in a blendedsource material stream. Other types and/or combinations of sensors asdisclosed herein (or as otherwise known to one skilled in the art) maybe employed to control blending of source material streams.

Various types of control elements may be utilized with a dispensingapparatus as described herein. The term “control element” may includegeneral purpose or special purpose computers arranged to executepredefined or user-defined instruction sets, programmable logiccontrollers, signal comparators, control valves, mass flow controllers,pressure regulators, actuators, and the like.

At least one sensing element arranged to generate an output signalcorrelative of dispensation of a desired amount of fluid from, orcorrelative of an approach to gas saturation of fluid dispensed by, afirst pressure dispense apparatus may include: (A) a pressure transducerarranged to sense pressure of fluid dispensed by a pressure dispenseapparatus; (B), a sensor (e.g., a scale, a strain gauge, or the like)arranged to sense weight of (i) fluid contained within an interiorvolume of a pressure dispensing apparatus, or (ii) the vessel and fluidcontained within the vessel of a pressure dispense apparatus; or (C) aflow sensor (such as an integrating flow meter) arranged to senseaggregate volume or aggregate mass of fluid dispensed by a pressuredispense apparatus. Sensing of a condition and generating an outputsignal may include comparing a signal generated by a sensing elementwith a predefined value indicative of an amount of fluid to be dispensedfrom the first pressure dispense apparatus or indicative of apre-saturation state of fluid dispensed by the first pressure dispenseapparatus, to generate the output signal. At least one sensing elementmay be associated with each pressure dispense apparatus of a dispensingsystem.

As noted previously, fluid from a first pressure dispensing apparatus iscombined with fluid from a second pressure dispensing apparatus uponsensing of a predefined condition correlative of dispensation of adesired amount of fluid from, or correlative of an approach to gassaturation of fluid dispensed by, the first pressure dispense apparatus,and the combined fluid flow is supplied to a desired point of use. Afterfluid is fully depleted from the first pressure dispensing apparatus,fluid may be dispensed solely from the second pressure dispensingapparatus for some time to the same desired point of use, and the firstpressure dispense apparatus may be replenished with fluid (or a thirdpressure dispense apparatus may be substituted for the first pressuredispense apparatus). Upon sensing of a predefined condition correlativeof dispensation of a desired amount of fluid from, or correlative of anapproach to gas saturation of fluid dispensed by, the second pressuredispense apparatus, fluid from the second pressure dispense apparatusmay be combined with fluid from another pressure dispense apparatus,such as the replenished third pressure dispense apparatus or a thirdpressure dispense apparatus. As a result, fluid may be supplied on asubstantially continuous basis to a desired point of use, whilemaintaining such fluid at a desirably low gas saturation level. Theprocess of sensing a specified condition associated with one pressuredispense container (or the output thereof) and initiating dispensationfrom a new pressure dispense container for combining flow of fluids frommultiple pressure dispense containers, may be repeated as necessary.

In certain embodiments, a fluid dispensing system includes a firstpressure dispense apparatuses with a first collapsible liner arranged tocontain fluid therein, and includes a second pressure dispenseapparatuses with a second collapsible liner arranged to contain fluidtherein. In other embodiments, each pressure dispense apparatus may bedevoid of a liner, to permit pressure dispensing by direct contact ofpressurized gas with fluid to be dispensed.

A fluid dispensing system according to one embodiment utilizing pressuresensing to initiate combining of streams from first and second pressuredispense apparatuses is illustrated in FIG. 13. The dispensing system600 includes a first portion 601A with a first pressure dispenseapparatus 602A, first degassing and/or filtering reservoir 640A, andaccompanying flow control components, and includes a second portion 602Bwith a second pressure dispense apparatus 602B, second degassing and/orfiltering reservoir 604B, and accompanying flow control components. Eachpressure dispense apparatus 602A, 602B includes a substantially rigidcontainer 610A, 610B and a collapsible liner 612A, 612B with aninterstitial space 613A, 613B therebetween. Each pressure dispenseapparatus 602A, 602B includes a cap 602A, 602B with a gas inlet conduit617A, 617B (coupled to a pressurized gas source 616A, 616B), a sourcematerial (e.g., liquid) outlet conduit 620A, 620B (arranged to receiveliquid from a dip tube 613A, 613B within the liner 612A, 612B), and agas vent conduit 630A, 630B (arranged to vent headspace gas from withinthe liner 612A, 612B). Each source material (e.g., liquid) outletconduit 620A, 620B has an associated pressure transducer 622A, 622B, acontrol valve 624A, 624B, and a check valve 625A, 625B disposed upstreamof the reservoir 640A, 640B. Each gas vent conduit 630A, 630B has anassociated vent 631A, 631B (which may optionally be coupled to a vacuumsource (not shown)), a control valve 634A, 634B, and a check valve 635A,635B disposed upstream of the reservoir 640A, 640B. Each reservoir 640A,640B includes an upper portion 642A, 642B receiving the source materialoutlet conduit 620A, 620B, receiving the gas vent conduit 630A, 630B,and including a downstream gas outlet conduit 648A, 648B leading to acontrol valve 649A, 649B, a tee 651, an additional gas check valve 652,and a single gas drain 653. Each reservoir 640A, 640B further includes alower portion 641A, 641B including a liquid outlet 646A, 646B leading toa control valve 647A, 647B, a tee 650, and a single dispensation conduit655. Sensors 644A, 644B, 645A, 645B associated with the reservoirs 640A,640B may be used in conjunction with the control valves 647A, 647B,649A, 649B to maintain a desired liquid level within the reservoirs640A, 640B. Various components downstream of each pressure dispensingapparatus 602A, 602B may be included in a flow control module 608 thatmay optionally be located remotely from each pressure dispensingapparatus 602A, 602B. Various elements of the dispensing system 600(including but not limited to the pressurized gas sources and the flowcontrol module 608) may be operatively coupled to one or more controlelements 605, which may include one or more controllers.

In operation of the dispensing system 600, headspace gas initiallypresent in the liner 612 of the first pressure dispense apparatus 602Amay be removed through the gas vent conduit 630A, either to a vent 631Aor through the filtering and/or degassing reservoir 640A. Gas may alsobe vented from the liner 612A through the gas vent conduit 630A duringliquid dispensing. To initiate pressure dispensing of source material(e.g., liquid) from the first pressure dispense apparatus 602A,pressurized gas is supplied from the first pressurized gas source 616Ato the interstitial space 611A between the first container 610A and thefirst liner 612A. Source material present in the liner 612A is forcedthrough the dip tube 613A into the source material conduit 620A. At suchtime, the second pressure dispensing apparatus 602B may be idle butready to initiate dispensing.

Pressure of the dispensed source material is sensed by the pressuretransducer 622A, and the source material flows into the firstfiltering/degassing reservoir 640 (which promotes removal of gas fromthe source material), and source material flows through outlet conduit646A and tee 650 to the dispensation conduit 655. A predeterminedpressure setpoint for initiating combined dispensing by the first andsecond dispensing apparatuses may be established empirically, such as bymodeling or measuring gas content in source material (or gas saturationcondition) as a function of pressure. A setpoint for initiating combineddispensing by multiple pressure dispense apparatuses may be selected atany suitable level, but is preferably establishing at a levelcorresponding to a source material that has not yet been highlysaturated with gas, so that blending of source material streams may beinitiated when the source material is in a pre-saturated state toprevent dispensation of saturated source material to a point of use.When the first pressure transducer 622A detects a pressure equaling thesetpoint, the transducer 622 generates an output signal that may be usedby at least one control element 605 to initiate dispensing of sourcematerial (e.g., liquid) by the second dispensing apparatus 602B.Operation of the second dispensing apparatus 602B commencessubstantially the same as the first dispensing apparatus 602A, with aflow of source material from the second dispensing apparatus 602Bflowing through the second filtering/degassing reservoir 640B to mergewith a flow of source material from the first pressure dispensingapparatus 602A at the tee 650, whereby the combined streams flow throughthe single dispensation conduit 655 to a desired point of use. Bycombining streams of source material from the first and second pressuredispensing apparatuses 602A, 602B, the gas saturation level of theresulting fluid may be maintained below acceptable levels, and greaterpercentage of fluid may be dispensed with a commensurate reduction influid waste.

A fluid dispensing system according to one embodiment utilizing weightsensing to initiate combining of streams from first and second pressuredispense apparatuses is illustrated in FIG. 14. The dispensing system700 includes a first portion 701A with a first pressure dispenseapparatus 702A, first degassing and/or filtering reservoir 740A, andaccompanying flow control components, and includes a second portion 702Bwith a second pressure dispense apparatus 702B, second degassing and/orfiltering reservoir 704B, and accompanying flow control components. Eachpressure dispense apparatus 702A, 702B includes a substantially rigidcontainer 710A, 710B and a collapsible liner 712A, 712B with aninterstitial space 713A, 713B therebetween. Weight of each pressuredispense apparatus is sensed with a scale 706A, 706B. Each pressuredispense apparatus 702A, 702B includes a cap 702A, 702B with a gas inletconduit 717A, 717B (coupled to a pressurized gas source 716A, 716B), asource material (e.g., liquid) outlet conduit 720A, 720B (arranged toreceive liquid from a dip tube 713A, 713B within the liner 712A, 712B),and a gas vent conduit 730A, 730B (arranged to vent headspace gas fromwithin the liner 712A, 712B). Each source material (e.g., liquid) outletconduit 720A, 720B has an associated a control valve 724A, 724B, and acheck valve 725A, 725B disposed upstream of the reservoir 740A, 740B.Each gas vent conduit 730A, 730B has an associated vent 731A, 731B(which may optionally be coupled to a vacuum source (not shown)), acontrol valve 734A, 734B, and a check valve 735A, 735B disposed upstreamof the reservoir 740A, 740B. Each reservoir 740A, 740B includes an upperportion 742A, 742B receiving the source material outlet conduit 720A,720B, receiving the gas vent conduit 730A, 730B, and including adownstream gas outlet conduit 748A, 748B leading to a control valve749A, 749B, a tee 751, an additional gas check valve 752, and a singlegas drain 753. Each reservoir 740A, 740B further includes a lowerportion 741A, 741B including a liquid outlet 746A, 746B leading to acontrol valve 747A, 747B, a tee 750, and a single dispensation conduit755. Sensors 744A, 744B, 745A, 745B associated with the reservoirs 740A,740B may be used in conjunction with the control valves 747A, 747B,749A, 749B to maintain a desired liquid level within the reservoirs740A, 740B. Various components downstream of each pressure dispensingapparatus 702A, 702B may be included in a flow control module 708 thatmay optionally be located remotely from each pressure dispensingapparatus 702A, 702B. Various elements of the dispensing system 700(including but not limited to the pressurized gas sources and the flowcontrol module 708) may be operatively coupled to one or more controlelements 705, which may include one or more controllers.

In operation of the dispensing system 700, headspace gas initiallypresent in the liner 712 of the first pressure dispense apparatus 702Amay be removed through the gas vent conduit 730A, either to a vent 731Aor through the filtering and/or degassing reservoir 740A. Gas may alsobe vented from the liner 712A through the gas vent conduit 730A duringliquid dispensing. To initiate pressure dispensing of source material(e.g., liquid) from the first pressure dispense apparatus 702A,pressurized gas is supplied from the first pressurized gas source 716Ato the interstitial space 711A between the first container 710A and thefirst liner 712A. Source material present in the liner 712A is forcedthrough the dip tube 713A into the source material conduit 720A. At suchtime, the second pressure dispensing apparatus 702B may be idle butready to initiate dispensing. Weight of the first pressure dispensingapparatus 702A is sensed by the scale 706A. Source material flows intothe first filtering/degassing reservoir 740, and source material flowsthrough outlet conduit 746A and tee 750 to the dispensation conduit 755.As source material is dispensed from the first pressure dispenseapparatus 702A, the weight of such apparatus 702A is reduced. Apredetermined weight setpoint for initiating combined dispensing by thefirst and second dispensing apparatuses may be established empirically,such as by modeling or measuring gas saturation as a function of weightof source material remaining in the a pressure dispense container. Whenthe first scale 706A detects a weight equaling the setpoint, the scale706A generates an output signal that may be used by at least one controlelement 705 to initiate dispensing of source material (e.g., liquid) bythe second dispensing apparatus 702B. Operation of the second dispensingapparatus 702B commences substantially the same as the first dispensingapparatus 702A, with a flow of source material from the seconddispensing apparatus 702B flowing through the second filtering/degassingreservoir 740B to merge with a flow of source material from the firstpressure dispensing apparatus 702A at the tee 750, whereby the combinedstreams flow through the single dispensation conduit 755 to a desiredpoint of use. Combining streams of source material from the first andsecond pressure dispensing apparatuses 702A, 702B permits the gassaturation level of the resulting fluid to be maintained belowacceptable levels, and greater percentage of fluid may be dispensed witha commensurate reduction in fluid waste.

A fluid dispensing system according to one embodiment utilizing flowsensing to initiate combining of streams from first and second pressuredispense apparatuses is illustrated in FIG. 15. The dispensing system800 includes a first portion 801A with a first pressure dispenseapparatus 802A, first degassing and/or filtering reservoir 840A, andaccompanying flow control components, and includes a second portion 802Bwith a second pressure dispense apparatus 802B, second degassing and/orfiltering reservoir 804B, and accompanying flow control components. Eachpressure dispense apparatus 802A, 802B includes a substantially rigidcontainer 810A, 810B and a collapsible liner 812A, 812B with aninterstitial space 813A, 813B therebetween. Each pressure dispenseapparatus 802A, 802B includes a cap 802A, 802B with a gas inlet conduit817A, 817B (coupled to a pressurized gas source 816A, 816B), a sourcematerial (e.g., liquid) outlet conduit 820A, 820B (arranged to receiveliquid from a dip tube 813A, 813B within the liner 812A, 812B), and agas vent conduit 830A, 830B (arranged to vent headspace gas from withinthe liner 812A, 812B). Each source material (e.g., liquid) outletconduit 820A, 820B has an associated flow sensor (e.g., totalizing flowsensor) 823A, 823B, a control valve 824A, 824B, and a check valve 825A,825B disposed upstream of the reservoir 840A, 840B. Each gas ventconduit 830A, 830B has an associated vent 831A, 831B (which mayoptionally be coupled to a vacuum source (not shown)), a control valve834A, 834B, and a check valve 835A, 835B disposed upstream of thereservoir 840A, 840B. Each reservoir 840A, 840B includes an upperportion 842A, 842B receiving the source material outlet conduit 820A,820B, receiving the gas vent conduit 830A, 830B, and including adownstream gas outlet conduit 848A, 848B leading to a control valve849A, 849B, a tee 851, an additional gas check valve 852, and a singlegas drain 853. Each reservoir 840A, 840B further includes a lowerportion 841A, 841B including a liquid outlet 846A, 846B leading to acontrol valve 847A, 847B, a tee 850, and a single dispensation conduit855. Sensors 844A, 844B, 845A, 845B associated with the reservoirs 840A,840B may be used in conjunction with the control valves 847A, 847B,849A, 849B to maintain a desired liquid level within the reservoirs840A, 840B. Various components downstream of each pressure dispensingapparatus 802A, 802B may be included in a flow control module 808 thatmay optionally be located remotely from each pressure dispensingapparatus 802A, 802B. Various elements of the dispensing system 800(including but not limited to the pressurized gas sources and the flowcontrol module 808) may be operatively coupled to one or more controlelements 805, which may include one or more controllers.

In operation of the dispensing system 800, headspace gas initiallypresent in the liner 812 of the first pressure dispense apparatus 802Amay be removed through the gas vent conduit 830A, either to a vent 831Aor through the filtering and/or degassing reservoir 840A. Gas may alsobe vented from the liner 812A through the gas vent conduit 830A duringliquid dispensing. To initiate pressure dispensing of source material(e.g., liquid) from the first pressure dispense apparatus 802A,pressurized gas is supplied from the first pressurized gas source 816Ato the interstitial space 811A between the first container 810A and thefirst liner 812A. Source material present in the liner 812A is forcedthrough the dip tube 813A into the source material conduit 820A. At suchtime, the second pressure dispensing apparatus 802B may be idle butready to initiate dispensing. Flow (e.g., totalized flow) of thedispensed source material is sensed by the flow sensor 823A, and thesource material flows into the first filtering/degassing reservoir 840(which promotes removal of gas from the source material), and sourcematerial flows through outlet conduit 846A and tee 850 to thedispensation conduit 855. A totalizing flow sensor may be used, oroutput of a non-totalizing flow sensor may be totalized by a computingdevice such as may be embodied in the control elements 805. The flowsensor 823A may optionally embody a mass flow controller. Apredetermined totalized flow setpoint for initiating combined dispensingby the first and second dispensing apparatuses may be establishedempirically, such as by modeling or measuring gas saturation as afunction of totalized flow. When the first flow sensor 823A detects atotalized flow equaling the setpoint, the sensor 823A generates anoutput signal that may be used by at least one control element 805 toinitiate dispensing of source material (e.g., liquid) by the seconddispensing apparatus 802B. Operation of the second dispensing apparatus802B commences substantially the same as the first dispensing apparatus802A, with a flow of source material from the second dispensingapparatus 802B flowing through the second filtering/degassing reservoir840B to merge with a flow of source material from the first pressuredispensing apparatus 802A at the tee 850, whereby the combined streamsflow through the single dispensation conduit 855 to a desired point ofuse. By combining streams of source material from the first and secondpressure dispensing apparatuses 802A, 802B, the gas saturation level ofthe resulting fluid may be maintained below acceptable levels, andgreater percentage of fluid may be dispensed with a commensuratereduction in fluid waste.

FIG. 12 provides comparative results of a simulations including theblending of output streams of first and second pressure dispenseapparatuses. An actual system may need to take into account lengthened(e.g., double) pressurization time for both pressure dispense apparatusafter blending of source material commences. The modeled system includeda 200 liter liner-based pressure dispense apparatus, with a 65 ml/minliquid withdrawal rate, a 30 psig drive pressure, and a 3 cm radiusbubble initially present in the liner. FIG. 12 presents dissolved gassaturation pressure (in Pascals) versus time (in days) for simulationsmodeling gas released from folds during pressure dispense of fluid from(A) a 200 liter collapsible film-based container liner with zeroheadspace, (B) a 200 liter collapsible film-based container liner withnormal headspace, and (C) a first 200 liter collapsible film-basedcontainer liner with normal headspace until a transition at .about.3.7days, with admixing of fluid dispensed by the first liner with fluiddispensed by a second 200 liter liner thereafter. The transition shownat .about.3.7 days (when 10 liters of fluid source material remained inthe first liner) represents the initiation of combined dispensing by thefirst and second pressure dispense apparatuses, with 50% of theresulting combined stream provided by each pressure dispense apparatus.The modeled results show a significant drop in gas saturation pressureof the combined stream starting at the transition, thereby demonstratingefficacy of the inventive system and method in reducing gas saturationlevels and enabling dispensation of a greater percentage of sourcematerial from a pressure dispense container.

While the invention has been has been described herein in reference tospecific aspects, features and illustrative embodiments of theinvention, it will be appreciated that the utility of the invention isnot thus limited, but rather extends to and encompasses numerous othervariations, modifications and alternative embodiments, as will suggestthemselves to those of ordinary skill in the field of the presentinvention, based on the disclosure herein. Any one or more featuresdescribed in connection with one or more embodiment(s) are contemplatedto combined with one or more features of any other embodiment(s), unlessspecifically indicated to the contrary herein. Correspondingly, theinvention as hereinafter claimed is intended to be broadly construed andinterpreted, as including all such variations, modifications andalternative embodiments, within its spirit and scope.

1.-78. (canceled)
 79. A fluid dispensing system, comprising: a gasseparation device adapted to remove gas from a liquid stream, including:a reservoir body defining an interior volume including therein afiltration medium adapted to permit passage of liquid but preventpassage of bubbles, the reservoir body defining a fluid inlet, a liquidoutlet arranged to receive liquid passing through the filtration medium,and a gas outlet arranged to receive gas accumulated from bubblesprevented from passing through the filtration medium; a level sensor insensory communication with the interior volume and arranged to generatean output signal indicative of a liquid level within the interiorvolume; and a valve in fluid communication with the gas outlet, whereinthe gas separation device is configured to open the valve to vent gasfrom the interior volume responsive to the output signal.
 80. The fluiddispensing system of claim 79, wherein the level sensor is a capacitivesensor.
 81. The fluid dispensing system of claim 79, comprising apressure dispense apparatus coupled to the fluid inlet of the gasseparation device.
 82. The fluid dispensing system of claim 81, whereinthe pressure dispense apparatus includes a collapsible liner disposedwithin an outer container and defining an interstitial space between thecollapsible liner and the outer container, the interstitial spaceadapted to receive pressurized gas for compression of the liner todispense fluid from the liner.
 83. The fluid dispensing system of claim82, wherein the pressure dispense apparatus is coupled to the fluidinlet of the gas separation device via a connector mounted to thepressure dispense apparatus.
 84. The fluid dispensing system of claim83, wherein the gas separation device is distinct from and disposeddownstream of the connector.
 85. The fluid dispensing system of claim79, further comprising an empty detect apparatus adapted to detect anempty state or approach to empty state of said pressure dispenseapparatus.
 86. The fluid dispensing system of claim 85, wherein saidempty detect apparatus comprises a pressure transducer configured tosense pressure droop of fluid dispensed from said pressure dispenseapparatus and to responsively generate a corresponding output signal.87. A method of delivering a gas free chemical comprising: flowing aliquid through a reservoir body defining an interior volume and having afiltration medium disposed within the interior volume, the filtrationmedium configured to permit passage of the liquid but prevent passage ofbubbles entrained in the liquid, the reservoir body including areservoir liquid outlet arranged to receive the liquid passing throughthe filtration medium and a reservoir gas outlet arranged to receive gasaccumulated from bubbles prevented from passing through the filtrationmedium; sensing a liquid level in the interior volume of the reservoirbody; and venting gas from the reservoir gas outlet when the liquidlevel in the interior volume of the reservoir body is below apredetermined level.
 88. The method of claim 87, wherein the step ofsensing a liquid level is performed with a level sensor that generatesan output signal indicative of the liquid level within the interiorvolume.
 89. The method of claim 88, wherein the step of venting gas fromthe reservoir gas outlet is performed with a valve configured to openbased on the output signal of the level sensor.
 90. The method of claim87, comprising: detecting a pressure droop in the liquid; and generatingan output signal corresponding to the pressure droop.